how many kwh does a mud pump use manufacturer

A mud pump or drilling mud pump is used to circulate drilling mud on a drilling rig at high pressure. The mud is circulated down through the drill string, and back through the annulus at high pressures. Mud pumps are typically positive displacement pumps, otherwise known as reciprocating pumps. Mud pumps are ideal wherever a lot of fluid needs to be pumped under high pressure. They are considered an essential part of most oil well drilling rigs. Mud pumps can deliver high concentration and high viscosity slurry in a stable flow, making them adaptable to many uses.

Mud pumps are special-purpose pumps, particularly used for moving and circulating drilling fluids and other similar fluids in several applications such as mining and onshore and offshore oil & gas. Mud pumps are a piston/plunger cylinder systems that are used to transfer fluids at substantially high pressures. These pumps are operated in rugged and hostile environments and thus, are bulky and robust. These pumps can draw power from various sources. However, electricity and diesel are widely used sources. Diesel-driven mud pumps are well suited for remote and isolated applications where electricity is not continuously available. These pumps have two major sub-assemblies namely fluid and power ends.  The power end consumes power and drives the fluid end to pump the mud. The mud pump market is largely driven by the rising demand for oil & gas.

COVID-19 pandemic has shut-down the production of various products in the  mud pumps industry, mainly owing to the prolonged lockdown in major global countries. This has hampered the growth of mud pumps market  significantly from last few months, as is likely to continue during 2020.

COVID-19 has already affected the sales of equipment and machinery in the first quarter of 2020 and is likely to cause a negative impact on the market growth throughout the year.

The major demand for equipment and machinery was previously noticed from giant manufacturing countries including the U.S., Germany, Italy, the UK, and China, which is badly affected by the spread of coronavirus, thereby halting the demand for equipment and machinery.

Further, potential impact of the lockdown is currently vague and financial recovery of companies is totally based on its cash reserves. Equipment and machinery companies can afford a full lockdown only for a few months, after which the players would have to modify their investment plans.

Equipment and machinery manufacturers must focus on protecting their workforce, operations, and supply chains to respond toward immediate crises and find new ways of working after COVID-19

A mud pump has its use in drilling fluids, mining and various purpose like that and its increase in demand for such purpose is the  factor that drives its growth.increased demand for directional and horizonal drilling

The main drivers for the growth of this market are the increased demand for directional and horizonal drilling, higher pressure handling capabilities, and a number of new oil discoveries. The global rise in demand for energy boosts the global mud pumps as according to its immense use in  market. However, high cost of drilling, environmental risks, and changing government regulations for energy and power may hinder the growth of the market.Innovation in technology

Innovation in technology is the key for further growth for example, MTeq uses Energy Recovery’s Pressure exchanger technology in the drilling industry, as the ultimate engineered solution to increase productivity and reduce operating costs in pumping process by rerouting rough fluids away from high-pressure pumps, which helps reduce the cost of maintenance for operators. As there is increase in technology , so these kind of new innovations in traditional ways that eases the work and reduce the difficulties  becomes the factor to increase the growth of market.

Key benefits of the report:This study presents the analytical depiction of the mud pumps market along with the current trends and future estimations to determine the future of the market

Key Market Players Kirloskar Ebara Pumps Limited, Flowserve, Goulds Pumps, Shijiazhuang Industrial Pump Factory Co. Ltd., Halliburton, Xylem Inc., KSB Group, Excellence Pump Industry Co. Ltd., Weir Group, SRS Crisafulli Inc.

This mud pump will deliver the consistent flow of drilling fluid that is vital to HDD pipeline drilling projects. Suction inlet valve suspends charged flow during drill rod makeup and breakout process, keeping excess drilling fluid from escaping as drill pipes separate. The lubrication pump is driven off the auxiliary pad on the engine. It provides 55 psi (3.8 bar) of continuous crankshaft lubrication. The internal hydraulic reservoir has a capacity of 49 gal (185.5 L). Clutch with continuous duty throw-out bearing allows for longer pump disengagement during drill rod makeup/breakout....

A triplex piston pump produces up to 435.3 gpm (1647.8 L/min), providing a continuous flow of drilling fluid during drill operations. An electric centrifugal pump provides constant flow, keeping the pump running cool and leading to a longer life for both pistons and liners. Remote pendant control allows operator to mount controls where it makes sense for them. The remote pendant control monitors mud rate and eliminates the need for stroke counter. The integrated liner wash tank eliminates the need for additional water containers or electricity when running the pump. An engine-mounted air...

Specifications Additional Components General Weights and Dimensions Weight: 26,600 lb (12,065.6 kg) Length: 19.1" (5.8 m) Width: 91.1" (231.4 cm) Height: 78" (198.1 cm) Controls Onboard: Open control station Remote: Tethered control box reaches 120" (36.6 m) Power Source Power source description: Non-detachable, onboard, open engine bay Engine description: CAT C9 or C9.3 ACERT IOPU EPA certification family: Tier 3 (EU Stage IIIA) or Tier 4i (EU Stage IIIB) Fuel type: Diesel Rated power: 350 hp (257.4 kW) Rated engine speed: 1800 rpm Fuel tank capacity: 191 gal (723 L) Electrical system:...

*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.

Choose a used Emsco FB-1600 Triplex Mud Pump from our inventory selection and save yourself some money on your next shallow drilling oilfield project. This Emsco FB-1600 Triplex Mud Pump is used and may show some minor wear.

We offer wholesale pricing on new Emsco FB-1600 Triplex Mud Pump and pass the savings on to you. Contact us to compare prices of different brands of Mud Pump. This equipment is brand new and has never been used.

Our large network often has surplus Emsco FB-1600 Triplex Mud Pump that go unused from a surplus purchase or a project that was not completed. Contact us to see what Emsco FB-1600 Triplex Mud Pump we have in inventory. The surplus Emsco FB-1600 Triplex Mud Pump are considered new but may have some weathering depending on where it was stored. Surplus oilfield equipment is usually stored at a yard or warehouse.

We have refurbished Mud Pumpthat have been used and brought up to functional standards. It is considered a ready to use, working Mud Pump. Please contact us for more information about our refurbished Emsco FB-1600 Triplex Mud Pump. These Mud Pump have been used and brought up to functional standards. It is considered a working Mud Pump. Please contact us for more information about the product.

The NOV FC-1600 Triplex Mud Pump is made of rugged Fabriform construction and designed for optimum performance under extreme drilling conditions. It is compact and occupies less space, yet delivers unequaled performance. The pumps are backed by several decades of design and manufacturing experience, and are considered leaders in the field.

NOV FC-1600 Triplex Mud Pump is conservatively rated at relatively low rpm. This reduces the number of load reversals in heavily stressed components and increases the life of the fluid end parts through conservative speeds and valve operation.

The NOV FC-1600 Triplex Mud Pump design provides an inherently balanced assembly. No additional counterbalancing is required for smooth operation. No inertia forces are transmitted to the pumps’ mountings.

A Triplex Mud Pump sometimes referred to as a drilling mud pump or mud drilling pump. NOV FC-1600 Triplex Mud Pump is a reciprocating piston/plunger pump designed to circulate drilling fluid under high pressure (up to 7,500 psi) down the drill string and back up the annulus. A mud pump is an important part of the equipment used for oil well drilling.

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Mud pump is one of the most critical equipment on the rig; therefore personnel on the rig must have good understanding about it. We’ve tried to find the good training about it but it is very difficult to find until we’ve seen this VDO training and it is a fantastic VDO training about the basic of mud pumps used in the oilfield. Total length of this VDO is about thirteen minutes and it is worth to watch it. You will learn about it so quickly. Additionally, we also add the full detailed transcripts which will acceleate the learning curve of learners.

Powerful mud pumps pick up mud from the suction tank and circulate the mud down hole, out the bit and back to the surface. Although rigs usually have two mud pumps and sometimes three or four, normally they use only one at a time. The others are mainly used as backup just in case one fails. Sometimes however the rig crew may compound the pumps, that is, they may use three or four pumps at the same time to move large volumes of mud when required.

Rigs use one of two types of mud pumps, Triplex pumps or Duplex pumps. Triplex pumps have three pistons that move back-and-forth in liners. Duplex pumps have two pistons move back and forth in liners.

Triplex pumps have many advantages they weight 30% less than a duplex of equal horsepower or kilowatts. The lighter weight parts are easier to handle and therefore easier to maintain. The other advantages include;

• One of the more important advantages of triplex over duplex pumps, is that they can move large volumes of mud at the higher pressure is required for modern deep hole drilling.

Triplex pumps are gradually phasing out duplex units. In a triplex pump, the pistons discharge mud only when they move forward in the liner. Then, when they moved back they draw in mud on the same side of the piston. Because of this, they are also called “single acting.” Single acting triplex pumps, pump mud at a relatively high speeds. Input horsepower ranges from 220 to 2200 or 164 to 1641 kW. Large pumps can pump over 1100 gallons per minute, over 4000 L per minute. Some big pumps have a maximum rated pressure of over 7000 psi over 50,000 kPa with 5 inch/127 mm liners.

Here is a schematic of a triplex pump. It has three pistons each moving in its own liner. It also has three intake valves and three discharge valves. It also has a pulsation dampener in the discharge line.

Look at the piston at left, it has just completed pushing mud out of the liner through the open discharge valve. The piston is at its maximum point of forward travel. The other two pistons are at other positions in their travel and are also pumping mud. But for now, concentrate on the left one to understand how the pump works. The left piston has completed its backstroke drawing in mud through the open intake valve. As the piston moved back it instead of the intake valve off its seat and drew mud in. A strong spring holds the discharge above closed. The left piston has moved forward pushing mud through the now open discharge valve. A strong spring holds the intake valve closed. They left piston has completed its forward stroke they form the length of the liner completely discharging the mud from it. All three pistons work together to keep a continuous flow of mud coming into and out of the pump.

Crewmembers can change the liners and pistons. Not only can they replace worn out ones, they can also install different sizes. Generally they use large liners and pistons when the pump needs to move large volumes of mud at relatively low pressure. They use a small liners and pistons when the pump needs to move smaller volumes of mud at a relatively high pressure.

In a duplex pump, pistons discharge mud on one side of the piston and at the same time, take in mud on the other side. Notice the top piston and the liner. As the piston moves forward, it discharges mud on one side as it draws in mud on the other then as it moves back, it discharges mud on the other side and draws in mud on the side it at had earlier discharge it. Duplex pumps are therefore double acting.

Double acting pumps move more mud on a single stroke than a triplex. However, because of they are double acting they have a seal around the piston rod. This seal keeps them from moving as fast as a triplex. Input horsepower ranges from 190 to 1790 hp or from 142 to 1335 kW. The largest pumps maximum rated working pressure is about 5000 psi, almost 35,000 kPa with 6 inch/152 mm linings.

A mud pump has a fluid end, our end and intake and the discharge valves. The fluid end of the pump contains the pistons with liners which take in or discharge the fluid or mud. The pump pistons draw in mud through the intake valves and push mud out through the discharge valves.

The power end houses the large crankshaft and gear assembly that moves the piston assemblies on the fluid end. Pumps are powered by a pump motor. Large modern diesel/electric rigs use powerful electric motors to drive the pump. Mechanical rigs use chain drives or power bands (belts) from the rig’s engines and compounds to drive the pump.

A pulsation dampener connected to the pump’s discharge line smooths out surges created by the pistons as they discharge mud. This is a standard bladder type dampener. The bladder and the dampener body, separates pressurized nitrogen gas above from mud below. The bladder is made from synthetic rubber and is flexible. When mud discharge pressure presses against the bottom of the bladder, nitrogen pressure above the bladder resists it. This resistance smoothes out the surges of mud leaving the pump.

Here is the latest type of pulsation dampener, it does not have a bladder. It is a sphere about 4 feet or 1.2 m in diameter. It is built into the mud pump’s discharge line. The large chamber is form of mud. It has no moving parts so it does not need maintenance. The mud in the large volume sphere, absorbs this surges of mud leaving the pump.

A suction dampener smooths out the flow of mud entering into the pump. Crewmembers mount it on the triplex mud pump’s suction line. Inside the steel chamber is a air charged rubber bladder or diaphragm. The crew charges of the bladder about 10 to 15 psi/50 to 100 kPa. The suction dampener absorbs surges in the mud pump’s suction line caused by the fast-moving pump pistons. The pistons, constantly starts and stops the mud’s flow through the pump. At the other end of the charging line a suction pumps sends a smooth flow of mud to the pump’s intake. When the smooth flow meets the surging flow, the impact is absorbed by the dampener.

Workers always install a discharge pressure relief valve. They install it on the pump’s discharge side in or near the discharge line. If for some reason too much pressure builds up in the discharge line, perhaps the drill bit or annulus gets plugged, the relief valve opens. That opened above protects the mud pump and system damage from over pressure.

Some rig owners install a suction line relief valve. They install it on top of the suction line near the suction dampener. They mount it on top so that it won’t clog up with mud when the system is shut down. A suction relief valve protects the charging pump and the suction line dampener. A suction relief valve usually has a 2 inch or 50 mm seat opening. The installer normally adjusts it to 70 psi or 500 kPa relieving pressure. If both the suction and the discharged valves failed on the same side of the pump, high back flow or a pressure surge would occur. The high backflow could damage the charging pump or the suction line dampener. The discharge line is a high-pressure line through which the pump moves mud. From the discharge line, the mud goes through the stand pipe and rotary hose to the drill string equipment.

Mud pumps are used on drilling rigs. They are reciprocating pumps for circulating mud, making them ideal in the process of drilling oil wells. If you are looking for a mud pump for sale, a great place to get started is online, and HENDERSON is here to help educate and find the ideal mud pump for your drilling operation.

We are based in Houston, Texas, USA, and we are a leading supplier of re-manufactured and used drilling equipment to international and domestic drilling contractors. Mud pumps are among the types of drilling equipment we carry, and we offer them in different types, so you can be sure to find the right mud pump for sale that suits your needs and budget.

Triplex mud pump – We recommend the triplex mud pump for drilling applications that require a high pump pressure. One of the most common applications for a triplex mud pump is oil drilling, and it works by decreasing the volume of the working fluid being discharged to generate enough pressure to produce the flow.

A triplex mud pump comes with three pistons, where the middle piston is the one that generates more pressure to a crankshaft. However, be careful of high piston load, which can cause the excessive application of pressure that can lead to crankshaft failing or cracking. Be sure to explore our range of triplex mud pumps for sale here.

Quintuplex mud pump – These mud pumps are used to pump fluid during drilling operations, and they work as a continuous duty return piston. Their external bearings aid in the crankshaft’s support to ensure the proper function of the five eccentric sheaves.

Duplex mud pump – Use duplex mud pumps to make sure that the circulation of the mud being drilled or the supply of liquid reaches the bottom of the well from the mud cleaning system. Despite being older technology than the triplex mud pump, the duplex pumps can use either electricity or diesel, and maintenance is easy due to their binocular floating seals and safety valves.

The 2,200-hp mud pump for offshore applications is a single-acting reciprocating triplex mud pump designed for high fluid flow rates, even at low operating speeds, and with a long stroke design. These features reduce the number of load reversals in critical components and increase the life of fluid end parts.

The pump’s critical components are strategically placed to make maintenance and inspection far easier and safer. The two-piece, quick-release piston rod lets you remove the piston without disturbing the liner, minimizing downtime when you’re replacing fluid parts.

VATVA GIDC, Ahmedabad 195, Pushpak Industrial Estate, Old Nika Tube Compound Phase I, GIDC, Vatva, VATVA GIDC, Ahmedabad - 382445, Dist. Ahmedabad, Gujarat

Ramnath Industrial Park, Rajkot Ramnath Industrial Park, Kothariya Ring Road, Beside Murlidhar Way Bridge Aaji dem, Near Ramvan, Ramnath Industrial Park, Rajkot - 360002, Dist. Rajkot, Gujarat

mahila college circle, Bhavnagar FIRST FLOOR PLOT NO 851/B-4 K K AVENUE ROAD, KRUSHNANAGAR SHANTAM BUNGLOWS Blood Bank Road, mahila college circle, Bhavnagar - 364001, Dist. Bhavnagar, Gujarat

Amraiwadi, Ahmedabad No. 16, Bankar Estate, Near Anup Estate, Behind Bharat Party Plot National Highway No. 8, Amraiwadi, Amraiwadi, Ahmedabad - 380026, Dist. Ahmedabad, Gujarat

Near Chhotalal Cross Road, Odhav, Ahmedabad 6, Agrasen Estate Opposite LIG Quarters, D 44 Road, Near Chhotalal Cross Road, Odhav, Ahmedabad - 382415, Dist. Ahmedabad, Gujarat

Odhav, Ahmedabad 11, Karma Industrial Park, Kathwada, Odhav Ring Road Circle, Kathwada Singarva Road GIDC, Odhav, Ahmedabad - 382430, Dist. Ahmedabad, Gujarat

Sarkhe Highway, Ahmedabad No. 19, Ground Floor, Yogeswar Complex, Opposite Sola Overbridge, Near The Fern Hotel Gulab Tower Road, S.G Highway, Thaltej, Sarkhe Highway, Ahmedabad - 380054, Dist. Ahmedabad, Gujarat

As electricity rates continue to rise, several factors contribute to this. Climate-related events over the past few years, the rising cost of natural gas, and the current conflict in Europe are just a few and they show no signs of stopping. While the likelihood of a decrease in rates is far less possible than an increase, finding ways to save money on electricity can be tricky if you overthink it. While there are several organizations out there that can offer you different ways to save money by signing up for various products, the commonsense approach of conservation will save you money every time.

It’s easy to think this way when you are at home. Making sure lights are turned off when they aren’t being used, turning off televisions that aren’t being watched, and keeping an eye on the AC are just a few. But how do we implement the conservation of electricity in our MUDs? Water and wastewater plants take a lot of electricity to run and it’s not as simple as remembering to turn a light off to conserve energy. Director involvement in the conservation process begins with educating them on what steps they can take to help their plant to run more efficiently.

Equipment upgrades at your plant are a good place to start. At your wastewater plant, the blowers used in the aeration chambers run 24/7 and consume a lot of the plant’s energy. Making sure you are using turbo blowers instead of conventional ones is one way to save energy. The turbo blowers are about 10-20 percent more efficient and are smaller and quieter than conventional blowers. This may seem like a small amount but the annual savings are easily noticed when budget time comes around.

Pumps at the wastewater plant and the lift stations also consume a lot of electricity as there are several that are running constantly and others that come on as needed during peak usage times. Making sure that your district is using energy-efficient pumps and having the floats (sensor mechanisms that tell the pump when to turn on) set correctly are sure ways to conserve.

Operational modifications are another way to conserve energy at your plants. Energy-efficient lighting should be installed at the plants and only used at night. This seems like a simple one, but I can’t tell you how many plants I’ve been in that are all running their lights during the day. Installing a SCADA, which is an automated system that can monitor the plant and collect important data, can save you time and energy as it will help control the total process. It also will give your operator some peace of mind when daily maintaining your facilities.

Another way for your district to conserve energy is by joining an aggregation program such as the one Acclaim offers. Aggregating with other districts can save your district a lot of money by combining your load profile with other districts to procure a better rate per kWh. With all the volatility in the market today, it is best to lock in a lower rate now and avoid an impact on your budget in the future.

Established in 1991, Laxmi Pumps Private Limited has been producing LADA Submersible Pumps exclusively with reliable quality and excellent after-sales service. LADA is the brand under which our products are manufactured and marketed.

Established in 1991, Laxmi Pumps Private Limited has been producing LADA Submersible Pumps exclusively with reliable quality and excellent after-sales service. LADA is the brand under which our products are manufactured and marketed.

We are one of the renowned Manufacturers, Exporters and Suppliers of precision-engineered Mud Pumps in Gujarat (India). Our LX-series of Mud Pumps sold under the brand name “Laxmi” is manufacturing in compliance with international standards as our company isISO 9001: 2008 certified.

Developed by a team of highly qualified engineers using computer-aided designing and manufacturing technologies, our Mud Pumps are double-acting and piston (reciprocating) type. They are designed to endure high pressure and high discharge application. In addition, they have several in-built design and constructional features that ensure high efficiency without much electricity intake.

Our Mud Pumps are available in various models and can be ordered in bulk. In addition, we offer them at very economical prices and provide customized solutions.

Our Mud Pumps are duplex double acting reciprocating type made from a single piece alloy casting capable of handling high discharge and high pressure applications. These are ideally suitable for seismograph survey, water well, oil well, core drilling mud and cement service applications. Moreover, the pumps feature continuous tooth herring-bone gears fitted with eccentric for easy economical replacement.

We have the requisite technical and commercial expertise to expand our business to new horizons of growth. Company’s main strength is its Quality and Innovative designs. This is the reason why our products are well established as POWERSAVER PUMPS in the market.

Over the years, we have developed an ultramodern production unit spread over 550 Sq .ft of land. We have equipped our unit with the latest technologies and advanced machineries. Backed by these resources, we produce 15 pieces per month. Following are the equipment we have at our unit:

Industrial pumps are essential devices required in every phase of oil and gas operations. Basically, they help transfer process fluids from one point to another.

For example, a pump can be used to transfer crude oil from a storage tank to a pipeline and mud pumps are used to circulate drilling mud into the annulus of a drill bit and back to a storage tank for re-purification.

In oil and gas operations, process fluids can range from easy to difficult.  Depending on the nature of the substance you want to transfer and your required flow rate, you’ll need a suitable pump for your needs.

Various types of industrial pumps are utilized for fluid transfer in the oil and gas industry. Pumps used in O&G can be classified based on their design and construction and generally fall into 6 major categories:

Centrifugal pumps are the most common types of pumps used in the oil and gas industry. Centrifugal pumps use centrifugal force through the rotation of the pump impeller to draw fluid into the intake of the pump and force it through the discharge section via centrifugal force. The flow through the pump is controlled by discharge flow control valves.

Single stage centrifugal pumps are primarily used for transferring low-viscosity fluids that require high flow rates. They are typically used as part of a larger pump network comprising other centrifugal pumps like horizontal multistage pump units for crude oil shipping or water injection pumps used in secondary oil and gas recovery.

Plunger pumps are some of the most ubiquitous industrial pumps in the oil and gas industry. Plunger pumps use the reciprocating motion of plungers and pistons to pressurize fluid in an enclosed cylinder to a piping system. Plunger pumps are considered constant flow pumps since at a given speed, the flow rate is constant despite the system pressure. A relief valve is an essential part of any plunger pump discharge piping system to prevent overpressuring of the pump and piping system.

Plunger pumps require more frequent maintenance than centrifugal pumps due to the design of the moving parts. They also have a noisier operation than centrifugal pumps.

A progressive cavity pump is a type of positive displacement pump and is also known as an eccentric screw pump or cavity pump. It transfers fluid by means of the progress, through the pump, of a sequence of small, fixed shape, discrete cavities, as its rotor is turned. Progressive cavity pumps are used in high viscosity applications or if blending the of the pumped fluid is not desired.

Progressive cavity pumps are also considered constant flow pumps since at a given speed, the flow rate is relatively constant despite the system pressure. Flow slippage is normal at higher pressures. A relief valve is an essential part of any progressive cavity pump discharge piping system to prevent overpressuring of the pump and piping system.

Diaphragm pumps are one of the most versatile types of oil and gas pumps in the industry and transfer fluid through positive displacement with a valve and diaphragm. The working principle of this pump is that a decrease in volume causes an increase in pressure in a vacuum and vice versa.

Diaphragm pumps are suitable for high-volume fluid transfer operations in oil refineries. They also require much less maintenance than positive displacement pumps due to their fewer moving parts and less friction during operation and are available in compact designs.

On the downside, diaphragm pumps are susceptible to ‘winks’ – low-pressure conditions inside the system that slow down pumping operations. Fortunately, winks can be rectified by using a back-pressure regulator. For the same reason, they are not suitable for continuous or long-distance pumping operations as they generally don’t meet the high-pressure conditions required.

A gear pump uses the meshing of gears to pump fluid by displacement. Gear pumps are one of the most common types of positive displacement pumps for transferring industrial fluids.

Gear pumps are also widely used for chemical transfer applications for high viscosity fluids. There are two main variations: external gear pumps which use two external spur gears or timing gears that drive the internal gear set. The internal gears do not touch, so non-lubricating fluids can be pumped with external gear pumps. Internal gear pumps use a shaft driven drive gear to drive the internal mating gear. Gear pumps are positive displacement (or fixed displacement), meaning they pump a constant amount of fluid for each revolution.

Since the pumped fluid passes between the close gear tolerances, gear pumps are normally used for clean fluids. A relief valve is an essential component in the discharge piping system to protect the pump and piping from over pressurizing.

A metering pump moves a precise volume of liquid in a specified time period providing an accurate flow rate. Delivery of fluids in precise adjustable flow rates is sometimes called metering. The term “metering pump” is based on the application or use rather than the exact kind of pump used. Most metering pumps are simplex reciprocating pumps with a packed plunger or diaphragm liquid end. The diaphragm liquid end is preferred since the pumped fluid is sealed inside the diaphragm. No pumped liquid leaks to the atmosphere.

At IFS, we design and manufacture modular and custom process solutions to suit diverse oilfield applications. Our expert process skid manufacturers have engineered a range of products and solutions for upstream, midstream, and downstream sectors.

The invention relates generally to offshore drilling systems which are employed for drilling subsea wells. More particularly, the invention relates to an offshore drilling system which maintains a dual pressure gradient, one pressure gradient above the well and another pressure gradient in the well, during a drilling operation.

Deep water drilling from a floating vessel typically involves the use of a large- diameter marine riser, e.g. a 21 -inch marine riser, to connect the floating vessel"s surface equipment to a blowout preventer stack on a subsea wellhead. The floating vessel may be moored or dynamically positioned at the drill site. However, dynamically-positioned drilling vessels are predominantly used in deep water drilling. The primary functions of the marine riser are to guide the drill string and other tools from the floating vessel to the subsea wellhead and to conduct drilling fluid and earth-cuttings from a subsea well to the floating vessel. The marine riser is made up of multiple riser joints, which are special casings with coupling devices that allow them to be interconnected to form a tubular passage for receiving drilling tools and conducting drilling fluid. The lower end of the riser is normally releasably latched to the blowout preventer stack, which usually includes a flexible joint that permits the riser to angularly deflect as the floating vessel moves laterally from directly over the well. The upper end of the riser includes a telescopic joint that compensates for the heave of the floating vessel. The telescopic joint is secured to a drilling rig on the floating vessel via cables that are reeved to sheaves on riser tensioners adjacent the rig"s moon pool. The riser tensioners are arranged to maintain an upward pull on the riser. This upward pull prevents the riser from buckling under its own weight, which can be quite substantial for a riser extending over several hundred feet. The riser tensioners are

adjustable to allow adequate support for the riser as water depth and the number of riser joints needed to reach the blowout preventer stack increases. In very deep water, the weight of the riser can become so great that the riser tensioners would be rendered ineffective. To ensure that the riser tensioners work effectively, buoyant devices are attached to some of the riser joints to make the riser weigh less when submerged in water. The buoyant devices are typically steel cylinders that are filled with air or plastic foam devices.

The maximum practical water depth for current drilling practices with a large diameter marine riser is approximately 7,000 feet. As the need to add to energy reserves increases, the frontiers of energy exploration are being pushed into ever deeper waters, thus making the development of drilling techniques for ever deeper waters increasingly more important. However, several aspects of current drilling practices with a conventional marine riser inherently limit deep water drilling to water depths less than approximately 7,000 feet. The first limiting factor is the severe weight and space penalties imposed on a floating vessel as water depth increases. In deep water drilling, the drilling fluid or mud volume in the riser constitutes a majority of the total mud circulation system and increases with increasing water depth. The capacity of the 21 -inch marine riser is approximately 400 barrels for every 1,000 feet. It has been estimated that the weight attributed to the marine riser and mud volume for a rig drilling at a water depth of 6,000 feet is 1,000 to 1,500 tons. As can be appreciated, the weight and space requirements for a drilling rig that can support the large volumes of fluids required for circulation and the number of riser joints required to reach the seafloor prohibit the use of the 21 -inch riser, or any other large-diameter riser, for drilling at extreme water depths using the existing offshore drilling fleet.

The second limiting factor relates to the loads applied to the wall of a large- diameter riser in very deep water. As water depth increases, so does the natural period of the riser in the axial direction. At a water depth of about 10,000 feet, the natural period of the riser is around 5 to 6 seconds. This natural period coincides with the period of the

water waves and can result in high levels of energy being imparted on the drilling vessel and the riser, especially when the bottom end of the riser is disconnected from the blowout preventer stack. The dynamic stresses due to the interaction between the heave of the drilling vessel and the riser can result in high compression waves that may exceed the capacity of the riser.

In water depths 6,000 feet and greater, the 21 -in riser is flexible enough that angular and lateral deflections over the entire length of the riser will occur due to the water currents acting on the riser. Therefore, in order to keep the riser deflections within acceptable limits during drilling operations, tight station keeping is required. Frequently, the water currents are severe enough that station keeping is not sufficient to permit drilling operations to continue. Occasionally, water currents are so severe that the riser must be disconnected from the blowout preventer stack to avoid damage or permanent deformation. To prevent frequent disconnection of the riser, an expensive fairing may have to be deployed or additional tension applied to the riser. From an operational standpoint, a fairing is not desirable because it is heavy and difficult to install and disconnect. On the other hand, additional riser tensioners may over-stress the riser and impose even greater loads on the drilling vessel.

A third limiting factor is the difficulty of retrieving the riser in the event of a storm. Based on the large forces that the riser and the drilling vessel are already subjected to, it is reasonable to conclude that neither the riser nor the drilling vessel would be capable of sustaining the loads imposed by a hurricane. In such a condition, if the drilling vessel is a dynamically positioned type, the drilling vessel will attempt to evade the storm. Storm evasion would be impossible with 10,000 feet of riser hanging from the drilling vessel. Thus, in such a situation, the riser would have to be pulled up entirely.

In addition, before disconnecting the riser from the blowout preventer stack, operations must take place to condition the well so that the well may be safely abandoned. This is required because the well depends on the hydrostatic pressure of the mud column extending from the top end of the riser to the bottom of the well to

overcome the pore pressures of the formation. When the mud column in the riser is removed, the hydrostatic pressure gradient is significantly reduced and may not be sufficient to prevent formation fluid influx into the well. Operations to contain well pressure may include setting a plug, such as a storm packer, in the well and closing the blind ram in the blowout preventer stack.

After the storm, the drilling vessel would return to the drill site and deploy the riser to reconnect and resume drilling. In locations like Gulf of Mexico where the average annual number of hurricanes is 2.8 and the maximum warning time of an approaching hurricane is 72 hours, it would be necessary to disconnect and retrieve the riser every time there is a threat of hurricane in the vicinity of the drilling location. This, of course, would translate to huge financial losses to the well operator.

A fourth limiting factor, relates to emergency disconnects such as when a dynamically positioned drilling vessel experiences a drive off. A drive off is a condition when a floating drilling vessel loses station keeping capability, loses power, is in imminent danger of colliding with another marine vessel or object, or experiences other conditions requiring rapid evacuation from the drilling location. As in the case of the storm disconnect, well operations are required to condition the well for abandoning. However, there is usually insufficient time in a drive off to perform all of the necessary safe abandonment procedures. Typically, there is only sufficient time to hang off the drill string from the pipe/hanging rams and close the shear/blind rams in the blowout preventer before disconnecting the riser from the blowout preventer stack.

The well hydrostatic pressure gradient derived from the riser height is trapped below the closed blind rams when the riser is disconnected. Thus, the only barrier to the influx of formation fluid into the well is the closed blind rams since the column of mud below the blind rams is insufficient to prevent influx of formation fluid into the well. Prudent drilling operations require two independent barriers to prevent loss of well control. When the riser is disconnected from the blowout preventer stack, large volumes of mud will be dumped onto the seafloor. This is undesirable from both an economic and environmental standpoint.

A fifth limiting factor relates to marginal well control and the need for numerous casing points. In any drilling operation, it is important to control the influx of formation fluid from subsurface formations into the well to prevent blowout. Well control procedures typically involve maintaining the hydrostatic pressure of the drilling fluid column above the "open hole" formation pore pressure but, at the same time, not above the formation fracture pressure. In drilling the initial section of the well, the hydrostatic pressure is maintained using seawater as the drilling fluid with the drilling returns discharged onto the seafloor. This is possible because the pore pressures of the formations near the seafloor are close to the seawater hydrostatic pressure at the seafloor. While drilling the initial section of the well with seawater, formations having pore pressures greater than the seawater hydrostatic pressure may be encountered. In such situations, formation fluids may flow freely into the well. This uncontrolled flow of formation fluids into the well may be so great as to cause washouts of the drilled hole and, possibly, destroy the drilling location. To prevent formation fluid flow into the well, the initial section of the well may be drilled with weighted drilling fluids. However, the current practice of discharging fluid to the seafloor while drilling the initial section of the well does not make this option very attractive. This is because the large volumes of drilling fluids dumped onto the seafloor are not recovered. Large volumes of unrecovered weighted drilling fluids are expensive and, possibly, environmentally undesirable.

After the initial section of the well is drilled to an acceptable depth, using either seawater or weighted drilling fluid, a conductor casing string with a wellhead is run and cemented in place. This is followed by running a blowout preventer stack and marine riser to the seafloor to permit drilling fluid circulation from the drilling vessel to the well and back to the drilling vessel in the usual manner.

In geological areas characterized by rapid sediment deposition and young sediments, fracture pressure is a critical factor in well control. This is because fracture pressure at any point in the well is related to the density of the sediments resting above that point combined with the hydrostatic pressure of the column of seawater above.

These sediments are significantly influenced by the overlying body of water and the circulating mud column need only be slightly denser than seawater to fracture the formation. Fortunately, because of the higher bulk density of the rock, the fracture pressure rapidly increases with the depth of penetration below the seafloor and will present a less serious problem after the first few thousand feet are drilled. However, abnormally high pore pressures which are routinely encountered up to 2,000 feet below the seafloor continue to present a problem both when drilling the initial section of the well with seawater and when drilling beyond the initial section of the well with seawater or weighted drilling fluid. The challenge then becomes balancing the internal pressures of the formation with the hydrostatic pressure of the mud column while continuing drilling of the well. The current practice is to progressively run and cement casings, the next inside the previous, into the hole to protect the "open hole" sections possessing insufficient fracture pressure while allowing weighted drilling fluids to be used to overcome formation pore pressures. It is important that the well be completed with the largest practical casing through the production zone to allow production rates that will justify the high-cost of deep-water developments. Production rates exceeding 10,000 barrels per day are common for deep-water developments, and too small a production casing would limit the productivity of the well, making it uneconomical to complete. The number of casings run into the hole is significantly affected by water depth.

The multiple casings needed to protect the "open hole" while providing the largest practical casing through the production zone requires that the surface hole at the seafloor be larger. A larger surface hole in turn requires a larger subsea wellhead and blowout preventer stack and a larger blowout preventer stack requires a larger marine riser. With a larger riser, more mud is required to fill the riser and a larger drilling vessel is required to carry the mud and support the riser. This cycle repeats itself as water depth increases.

It has been identified that the key to breaking this cycle lies in reducing the hydrostatic pressure of the mud in the riser to that of a column of seawater and providing mud with sufficient weight in the well to maintain well control. Various concepts have

been presented in the past for achieving this feat; however, none of these concepts known in the prior art have gained commercial acceptance for drilling in ever deeper waters. These concepts can be generally grouped into two categories: the mud lift drilling with a marine riser concept and the riserless drilling concept. The mud lift drilling with a marine riser concept contemplates a dual-density mud gradient system which includes reducing the density of the mud returns in the riser so that the return mud pressure at the seafloor more closely matches that of seawater. The mud in the well is weighted to maintain well control. For example, U.S. Patent No. 3,603,409 to Watkins et al. and U.S. Patent No. 4,099,583 to Maus et al. disclose methods of injecting gas into the mud column in the marine riser to lighten the weight of the mud.

The riserless drilling concept contemplates eliminating the large-diameter marine riser as a return annulus and replacing it with one or more small-diameter mud return lines. For example, U.S. Patent No. 4,813,495 to Leach removes the marine riser as a return annulus and uses a centrifugal pump to lift mud returns from the seafloor to the surface through a mud return line. A rotating head isolates the mud in the well annulus from the open seawater as the drill string is run in and out of the well.

Drilling rates are significantly affected by the magnitude of the difference between formation pore pressure and mud column pressure. This difference, commonly called "overbalance", is adjusted by changing the density of the mud column. Overbalance is estimated as the additional pressure required to prevent the well from kicking, either during drilling or when pulling a drill string out of the well. This overbalance estimate usually takes into account factors like inaccuracies in predicting formation pore pressures and pressure reductions in the well as a drill string is pulled from the well. Typically, a minimum of 300 to 700 psi overbalance is maintained during drilling operations. Sometimes the overbalance is large enough to damage the formation.

The effect of overbalance on drilling rates varies widely with the type of drill bit, formation type, magnitude of overbalance, and many other factors. For example, in a typical drill bit and formation combination with a drilling rate of 30 feet per hour and an overbalance of 500 psi, it is common for the drilling rate to double to 60 feet per hour if

the overbalance is reduced to zero. An even greater increase in drilling rate can be achieved if the mud column pressure is decreased to an underbalanced condition, i.e. mud column pressure is less than formation pressure. Thus, to improve drilling rates, it may be desirable to drill a well in an underbalanced mode or with a minimum of overbalance. In conventional drilling operations, it is impractical to reduce the mud density to allow faster drilling rates and then increase the mud density to permit tripping the drill string. This is because the circulation time for the complete mud system lasts for several hours, thus making it expensive to repeatedly decrease and increase mud density. Furthermore, such a practice would endanger the operation because a miscalculation could result in a kick.

In general, in one aspect, a positive-displacement pump comprises multiple pumping elements, each pumping element comprising a pressure vessel with a first and a second chamber and a separating member disposed between the first and second chambers. The first chambers and the second chambers are hydraulically connected to receive and discharge fluid, wherein the separating members move within the pressure vessels in response to pressure differential between the first and second chambers. A valve assembly having suction and discharge valves communicates with the first chambers. The suction and discharge valves are operable to permit fluid to alternately flow into and out of the first chambers. A hydraulic drive alternately supplies hydraulic fluid to and withdraws hydraulic fluid from the second chambers such that the fluid discharged from the first chambers is substantially free of pulsation.

FIG. 2A is a detailed view of the well control assembly shown in FIG. 1. FIG. 2B is a detailed view of the mud lift module shown in FIG. 1. FIG. 2C is a detailed view of the pressure-balanced mud tank shown in FIG. 1.

FIGS. 3 A and 3B are cross sections of non-rotating subsea diverters. FIGS. 4A-4F are cross sections of rotating subsea diverters. FIG. 5 is a cross section of a wiper.

FIG. 8 is an elevation view of a subsea mud pump. FIG. 9A is a cross section of a diaphragm pumping element. FIG. 9B is a cross section of a piston pumping element.

FIG. 1 OB is a graph illustrating output characteristics of the open-circuit hydraulic drive shown in FIG. 10A. FIG. IOC illustrates the performance of the open-circuit hydraulic drive shown in

FIG. 16 is a diagram of a mud circulation system for the offshore drilling system shown in FIG. 1. FIG. 17 is a graph of depth versus pressure for a well drilled in a water depth of

FIG. 20A is a graph of depth versus pressure for a well drilled in a water depth of 5,000 feet for a dual-density mud gradient system which has a mudline pressure less than seawater pressure.

FIG. 21 illustrates the offshore drilling system of FIG. 1 with a mud lift module mounted on the seafloor. FIGS. 22A and 22B are elevation views of retrievable subsea components of the offshore drilling system shown in FIG. 21.

FIG. 26 is a top view of another embodiment of the return line riser shown in FIG. 23. FIG. 27 illustrates the offshore drilling system of FIG. 1 without a marine riser and with a mud lift module mounted on the seafloor.

FIG. 31 is a graph of depth versus pressure for the initial section of well drilled in a water depth of 5,000 feet using the subsea flow assembly shown in FIG. 30.

DETAILED DESCRIPTION FIG. 1 illustrates an offshore drilling system 10 where a drilling vessel 12 floats on a body of water 14 which overlays a pre-selected formation. The drilling vessel 12 is dynamically positioned above the subsea formation by thrusters 16 which are activated by on-board computers (not shown). An array of subsea beacons (not shown) on the seafloor 17 sends signals which are indicative of the location of the drilling vessel 12 to hydrophones (not shown) on the hull of the drilling vessel 12. The signals received by the hydrophones are transmitted to on-board computers. These on-board computers process the data from the hydrophones along with data from a wind sensor and other auxiliary position-sensing devices and activate the thrusters 16 as needed to maintain the drilling vessel 12 on station. The drilling vessel 12 may. also be maintained on station by using several anchors that are deployed from the drilling vessel to the seafloor. Anchors, however, are generally practical if the water is not too deep.

A drilling rig 20 is positioned in the middle of the drilling vessel 12, above a moon pool 22. The moon pool 22 is a walled opening that extends through the drilling vessel 12 and through which drilling tools are lowered from the drilling vessel 12 to the seafloor 17. At the seafloor 17, a conductor pipe 32 extends into a well 30. A conductor housing 33, which is attached to the upper end of the conductor pipe 32, supports the conductor pipe 32 before the conductor pipe 32 is cemented in the well 30. A guide structure 34 is installed around the conductor housing 33 before the conductor housing 33 is run to the seafloor 17. A wellhead 35 is attached to the upper end of a surface pipe 36 that extends through the conductor pipe 32 into the well 30. The wellhead 35 is of conventional design and provides a method for hanging additional casing strings in the well 30. The wellhead 35 also forms a structural base for a wellhead stack 37.

The wellhead stack 37 includes a well control assembly 38, a mud lift module 40, and a pressure-balanced mud tank 42. A marine riser 52 between the drilling rig 20 and the wellhead stack 37 is positioned to guide drilling tools, casing strings, and other equipment from the drilling vessel 12 to the wellhead stack 37. The lower end of the marine riser 52 is releasably latched to the pressure-balanced mud tank 42, and the upper end of the marine riser 52 is secured to the drilling rig 20. Riser tensioners 54 are provided to maintain an upward pull on the marine riser 52. Mud return lines 56 and 58, which may be attached to the outside of the marine riser 52, connect flow outlets (not shown) in the mud lift module 40 to flow ports in the moon pool 22. The flow ports in the moon pool 22 serve as an interface between the mud return lines 56 and 58 and a mud return system (not shown) on the drilling vessel 12. The mud return lines 56 and 58 are also connected to flow outlets (not shown) in the well control assembly 38, thus allowing them to be used as choke/kill lines. Alternatively, the mud return lines 56 and 58 may be existing choke/kill lines on the riser.

A drill string 60 extends from a derrick 62 on the drilling rig 20 into the well 30 through the marine riser 52 and the wellhead stack 37. Attached to the end of the drill string 60 is a bottom hole assembly 63, which includes a drill bit 64 and one or more drill collars 65. The bottom hole assembly 63 may also include stabilizers, mud motor, and

other selected components required for drilling a planned trajectory, as is well known in the art. During normal drilling operations, the mud pumped down the bore of the drill string 60 by a surface pump (not shown) is forced out of the nozzles of the drill bit 64 into the bottom of the well 30. The mud at the bottom of the well 30 rises up the well annulus 66 to the mud lift module 40, where it is diverted to the suction ends of subsea mud pumps (not shown). The subsea mud pumps boost the pressure of the returning mud flow and discharge the mud into the mud return lines 56 and/or 58. The mud return lines 56 and/or 58 then conduct the discharged mud to the mud return system (not shown) on the drilling vessel 12. The drilling system 10 is illustrated with two mud return lines 56 and 58, but it should be clear that a single mud return line or more than two mud return lines may also be used. Clearly the diameter and number of the return lines will affect the pumping requirements for the subsea mud pumps in the mud lift module 40. The subsea mud pumps must provide enough pressure to the returning mud flow to overcome the frictional pressure losses and the hydrostatic head of the mud column in the return lines. The wellhead stack 37 includes subsea diverters (not shown) which seal around the drill string 60 and form a separating barrier between the riser 52 and the well annulus 66. The riser 52 is filled with seawater so that the hydrostatic pressure of the fluid column at the seafloor or mudline or separating barrier formed by the subsea diverters is that of seawater. Filling the riser with seawater, as opposed to mud, reduces the riser tension requirements. The riser may also be filled with other fluids which have a lower specific gravity than the mud in the well annulus.

Well Control Assembly FIG. 2A shows the components of the well control assembly 38 which was previously illustrated in FIG. 1. As shown, the well control assembly 38 includes a lower marine riser package (LMRP) 44 and a subsea blowout preventer (BOP) stack 46. The BOP stack 46 includes a pair of dual ram preventers 70 and 72. However, other combinations, such as, a triple ram preventer combined with a single ram preventer may

be used. Additional preventers may also be required depending on the preferences of the drilling operator. The ram preventers are equipped with pipe rams for sealing around a pipe and shear/blind rams for shearing the pipe and sealing the well. The ram preventers 70 and 72 have flow ports 76 and 78, respectively, that may be connected to choke/kill lines (not shown). A wellhead connector 88 is secured to the lower end of the ram preventer 70. The wellhead connector 88 is adapted to mate with the upper end of the wellhead 35 (shown in FIG. 1).

The LMRP 44 includes annular preventers 90 and 92 and a flexible joint 94. However, the LMRP 44 may take on other configurations, e.g., a single annular preventer and a flexible joint. The annular preventers 90 and 92 have flow ports 98 and 100 that may be connected to choke/kill lines (not shown). The lower end of the annular preventer 90 is connected to the upper end of the ram preventers 72 by a LMRP connector 93. The flexible joint 94 is mounted on the upper end of the annular preventer 92. A riser connector 114 is attached to the upper end of the flexible joint 94. The riser connector 114 includes flow ports 113 which may be hydraulically connected to the flow ports 76, 78, 98, and 100. The LMRP 44 includes control modules (not shown) for operating the ram preventers 70 and 72, the annular preventers 90 and 92, various connectors and valves in the wellhead stack 37, and other controls as needed. Hydraulic fluid is supplied to the control modules from the surface through hydraulic lines (not shown) that may be attached to the outside of the riser 52 (shown in FIG. 1).

Mud lift module FIG. 2B shows the components of the mud lift module 40 which was previously illustrated in FIG. 1. As shown, the mud lift module 40 includes subsea mud pumps 102, a flow tube 104, a non-rotating subsea diverter 106, and a rotating subsea diverter 108. The lower end of the flow tube 104 includes a riser connector 110 which is adapted to mate with the riser connector 114 (shown in FIG. 2 A) at the upper end of the flexible joint 94. When the riser connector 110 mates with the riser connector 114, the flow ports 111 in the riser connector 110 are in communication with the flow ports 113 (shown in

FIG. 2 A) in the riser connector 114. A riser connector 112 is mounted at the upper end of the subsea diverter 108. The flow ports 111 in the riser connector 110 are connected to flow ports 116 in the riser connector 112 by pipes 118 and 120, and the pipes 118 and 120 are in turn hydraulically connected to the discharge ends of the subsea mud pumps 102. The suction ends of the subsea mud pumps 102 are hydraulically connected to flow outlets 125 in the flow tube 104.

The subsea diverters 106 and 108 are arranged to divert mud from the well annulus 66 (shown in FIG. 1) to the suction ends of the subsea mud pumps 102. The diverters 106 and 108 are also adapted to slidingly receive and seal around a drill string, e.g., drill string 60. When the diverters seal around the drill string 60, the fluid in the flow tube 104 or below the diverters is isolated from the fluid in the riser 52 (shown in FIG. 1) or above the diverters. The diverters 106 and 108 may be used alternately or together to sealingly engage a drill string and, thereby, isolate the fluid in the annulus of the riser 52 from the fluid in the well annulus 66. It should be clear that either the diverter 106 or 108 may be used alone as the separating medium between the fluid in the riser 52 and the fluid in the well annulus 66. A rotating blowout preventer (not shown), which could be included in the well control assembly 38 (shown in FIG. 2 A), may also be used in place of the diverters. The diverter 108 may also be mounted on the annular preventer 92 (shown in FIG. 2 A), and mud flow into the suction ends of the subsea pumps 102 may be taken from a point below the diverter.

Non-rotating subsea diverter FIG. 3 A shows a vertical cross section of the non-rotating subsea diverter 106 which was previously illustrated in FIG. 2B. As shown, the non-rotating subsea diverter 106 includes a head 126 that is fastened to a body 128 by bolts 130. However, other means, such as a screwed or radial latched connec