mud pump pressure problems brands

Working with some of the world"s leading suppliers of low-pressure equipment, we offer low-pressure pump packages and agitating units to suit every operation.

Cameron provides a range of integrated pump packages, including top- or rear-mount AC- or DC-electric drives, controls, manifolds, piping, and accessories for onshore and offshore applications.

Mud Pump Pressure is extremely important to the drilling process. The Mud Pump Pressure Gauge enables the driller to monitor the pressure while drilling. Any unusual change in pressure will alert the driller of down hole problems. Pressure too low could indicate washed out pipe or bit nozzle, loose joint or broken drill string, worn pump packing or liners, or lost returns due to formation breakdown. Pressure too high could indicate a plugged drill bit or an increase in mud density or viscosity. Reliable indication of mud pump pressure provides an early warning of circulation problems, enabling the driller to make corrections avoiding major problems.

A mud pump (sometimes referred to as a mud drilling pump or drilling mud pump), is a reciprocating piston/plunger pump designed to circulate drilling fluid under high pressure (up to 7,500 psi or 52,000 kPa) down the drill string and back up the annulus. A mud pump is an important part of the equipment used for oil well drilling and manufactured according to API specification 7K.

The advantages of the drilling mud pump include the ability to move high-solids-content fluids laden with abrasives, the ability to pump large particles, ease of operation and maintenance, reliability, and the ability to operate over a wide range of pressures and flow rates by changing the diameter of pump liners and pistons.

As an important equipment for oilfield drilling operation, a drilling mud pump delivers circulating high-pressure drilling fluid or drilling mud to the bottom of the oil well, flushes the bottom of the well, breaks the rock, cools, lubricates and clean the drill bit, and carries the cuttings back to the ground.

The drilling mud is also used to suspend and carry out drill cuttings from the drill bits as it is brought in and out of the hole. This ensures that the drill bit does not clog and overheat, and makes the entire drilling operation smooth and safe.

Rotational power is supplied to the mud pump through an external power source like a diesel engine or electric motor. The power end of the mud pump converts the rotational energy through a crankshaft to a reciprocating motion of pistons.

The pistons move back and forth in mud pump liners, exerting a force on the cylinder chamber. During the retraction of the piston, valves open to allow the fluid to be drawn into the cylinder. Once the piston has fully retracted, it is pushed back into the cylinder.

At this time the intake valves are closed and the exhaust valves open, allowing the piston to force the fluid out of the cylinder under pressure. Once the piston reaches its maximum depth into the cylinder, the exhaust valves close and the process repeats.

Check wiring connections. Reference control board diagnostics. With pressure control switch ON and pressure turned to MAXIMUM, use a test light to check for power between clutch terminals on control board.

When choosing a size and type of mud pump for your drilling project, there are several factors to consider. These would include not only cost and size of pump that best fits your drilling rig, but also the diameter, depth and hole conditions you are drilling through. I know that this sounds like a lot to consider, but if you are set up the right way before the job starts, you will thank me later.

Recommended practice is to maintain a minimum of 100 to 150 feet per minute of uphole velocity for drill cuttings. Larger diameter wells for irrigation, agriculture or municipalities may violate this rule, because it may not be economically feasible to pump this much mud for the job. Uphole velocity is determined by the flow rate of the mud system, diameter of the borehole and the diameter of the drill pipe. There are many tools, including handbooks, rule of thumb, slide rule calculators and now apps on your handheld device, to calculate velocity. It is always good to remember the time it takes to get the cuttings off the bottom of the well. If you are drilling at 200 feet, then a 100-foot-per-minute velocity means that it would take two minutes to get the cuttings out of the hole. This is always a good reminder of what you are drilling through and how long ago it was that you drilled it. Ground conditions and rock formations are ever changing as you go deeper. Wouldn’t it be nice if they all remained the same?

Centrifugal-style mud pumps are very popular in our industry due to their size and weight, as well as flow rate capacity for an affordable price. There are many models and brands out there, and most of them are very good value. How does a centrifugal mud pump work? The rotation of the impeller accelerates the fluid into the volute or diffuser chamber. The added energy from the acceleration increases the velocity and pressure of the fluid. These pumps are known to be very inefficient. This means that it takes more energy to increase the flow and pressure of the fluid when compared to a piston-style pump. However, you have a significant advantage in flow rates from a centrifugal pump versus a piston pump. If you are drilling deeper wells with heavier cuttings, you will be forced at some point to use a piston-style mud pump. They have much higher efficiencies in transferring the input energy into flow and pressure, therefore resulting in much higher pressure capabilities.

Piston-style mud pumps utilize a piston or plunger that travels back and forth in a chamber known as a cylinder. These pumps are also called “positive displacement” pumps because they literally push the fluid forward. This fluid builds up pressure and forces a spring-loaded valve to open and allow the fluid to escape into the discharge piping of the pump and then down the borehole. Since the expansion process is much smaller (almost insignificant) compared to a centrifugal pump, there is much lower energy loss. Plunger-style pumps can develop upwards of 15,000 psi for well treatments and hydraulic fracturing. Centrifugal pumps, in comparison, usually operate below 300 psi. If you are comparing most drilling pumps, centrifugal pumps operate from 60 to 125 psi and piston pumps operate around 150 to 300 psi. There are many exceptions and special applications for drilling, but these numbers should cover 80 percent of all equipment operating out there.

The restriction of putting a piston-style mud pump onto drilling rigs has always been the physical size and weight to provide adequate flow and pressure to your drilling fluid. Because of this, the industry needed a new solution to this age-old issue.

As the senior design engineer for Ingersoll-Rand’s Deephole Drilling Business Unit, I had the distinct pleasure of working with him and incorporating his Centerline Mud Pump into our drilling rig platforms.

In the late ’90s — and perhaps even earlier —  Ingersoll-Rand had tried several times to develop a hydraulic-driven mud pump that would last an acceptable life- and duty-cycle for a well drilling contractor. With all of our resources and design wisdom, we were unable to solve this problem. Not only did Miller provide a solution, thus saving the size and weight of a typical gear-driven mud pump, he also provided a new offering — a mono-cylinder mud pump. This double-acting piston pump provided as much mud flow and pressure as a standard 5 X 6 duplex pump with incredible size and weight savings.

The true innovation was providing the well driller a solution for their mud pump requirements that was the right size and weight to integrate into both existing and new drilling rigs. Regardless of drill rig manufacturer and hydraulic system design, Centerline has provided a mud pump integration on hundreds of customer’s drilling rigs. Both mono-cylinder and duplex-cylinder pumps can fit nicely on the deck, across the frame or even be configured for under-deck mounting. This would not be possible with conventional mud pump designs.

The second generation design for the Centerline Mud Pump is expected later this year, and I believe it will be a true game changer for this industry. It also will open up the application to many other industries that require a heavier-duty cycle for a piston pump application.

A properly serviced pulsation dampener is critical for your mud pumps’ efficiency, safety, and performance. Unfortunately, there aren’t many resources available to educate personnel on executing safe and effective servicing procedures. Please review the following steps with your personnel for safe pulsation dampener maintenance.

I’ve run into several instances of insufficient suction stabilization on rigs where a “standpipe” is installed off the suction manifold. The thought behind this design was to create a gas-over-fluid column for the reciprocating pump and eliminate cavitation.

When the standpipe is installed on the suction manifold’s deadhead side, there’s little opportunity to get fluid into all the cylinders to prevent cavitation. Also, the reciprocating pump and charge pump are not isolated.

The suction stabilizer’s compressible feature is designed to absorb the negative energies and promote smooth fluid flow. As a result, pump isolation is achieved between the charge pump and the reciprocating pump.

The isolation eliminates pump chatter, and because the reciprocating pump’s negative energies never reach the charge pump, the pump’s expendable life is extended.

Investing in suction stabilizers will ensure your pumps operate consistently and efficiently. They can also prevent most challenges related to pressure surges or pulsations in the most difficult piping environments.

Since the modern mud (or slush) pump was built approximately 60 years ago, the industry has widely accepted the three cylinder or triplex style pump. Triplex mud pumps are manufactured worldwide, and many companies have emulated the original design and developed an improved form of the triplex pump in the past decade.

As in all single acting pumps, the piston exerts a load on the crankshaft. The load is then transmitted to the crankshaft main bearings, which are set in their retainers in the pump frame or housing (see Figure 2).

The middle piston often exerts seven times greater bending moment on the crankshaft than either of the outer two pistons, causing the crankshaft to bend or flex. Where the force is directed along either of the outer two piston rods to their respective outer two crankshaft cams, the force is close to the bearings and the bending moment is considerably less. However, when the center piston is under pressure and the forces are directed down the middle connecting rod to the central cam, the distance of that central cam from either main bearing is large (sometimes 850 mm or 33 in), thus allowing for a large bending moment and resulting in significant flex in the crankshaft.

That the crankshaft is subjected to extreme bending loads and stress concentration areas is one of the drawbacks of the triplex design. Experience shows that all triplex pumps eventually exhibit crankshaft cracking if the operator is using the pump at higher loads and pressures, which is now common as drilling contractors are facing deeper, longer sections to drill. In the past, drillers rarely pushed the performance limitations of triplex pumps; 5,000 psi rated pumps were usually only operated at a maximum of 2,800 psi 90 percent of the time. Now contractors are encouraged to run pumps at the much higher pressures around 4,300 psi, only leaving a safety margin below the pressure relief valve setting. This means the crankshaft is subjected to extended maximum load, which inevitably shortens time to failure, probably exponentially.

Some may suggest that an increase in the number of pistons to improve flow rate will also reduce piston load. Although the middle piston load may be reduced for the same overall pump horsepower, the distance from the main bearings to the middle cam increases, which is not advantageous. For example, a five cylinder pump with the middle cam 50 in from the main bearing will have the same bending moment as a triplex with a 30 in middle cam to bearing distance. However, installing bearings close to the cams can reduce the cyclic failure problems on any pump.

For the drilling industry, the problem with this design is that few have managed to design a crankshaft where bearings can be installed anywhere other than at the crankshaft ends. Consequently, most pumps currently available have crankshafts unsupported close to the middle cam. With the middle area of the crankshaft unsupported, crankshaft failure is inevitable.

A triplex pump with a large load acting on the middle of the crankshaft of approximately 120,000 lbs and a typical distance of about 30 in from middle cam to either main bearing will exert a bending moment of 300,000 lb-ft on the crankshaft adjacent to the main bearing. If the bearing is not spherical, the bending moment where the shaft meets the bearing will coincide with the point on the shaft that the crank can no longer bend because it is restricted by the fixed bearing, which creates huge stress concentration. That load comes and goes cyclically every revolution of the pump. If the pump is rotating at 100 rpm or strokes, then in one week of drilling the crank will experience one million cycles of 300,000 lb-ft effectively switching on and off.

Another symptom of crankshaft deflection or bending is abnormal main gear wear patterns. The high unsupported load in the middle of the crankshaft effectively bows the shaft and consequently the bull gear is moved off alignment, and a strange wear pattern may appear on the gears. Although this is an undesirable occurrence, it is of little importance compared with crankshaft failure. It does explain abnormal wear on a pump used continuously at high pressure.

The case for welding or casting a crankshaft is arguable. While the cast crankshaft is strong and sometimes quite reliable, it is easy for casting anomalies like porosity and inclusions to be undetectable in inspection. Welded crankshafts always have a problem with the weld of the cams so close to a large diameter change, which can create stress concentration-induced problems. One way of avoiding both these problems is to have a modular crankshaft, which is assembled and disassembled without any welding or the need for subsequent heat-treating during manufacturing. All the crank components would be assembled from high quality forged parts that will last longer in any application and are unlikely to ever fail under normal or extreme conditions so long as the crankshaft is supported properly. (Figure 6 shows close bearing proximity to cams and spherical bearings.)

A pump that addresses these issues may be the solution. A quadraplex has minimal bending moments due to the close proximity of the main bearings to every cam (see Figure 7).

A fully assembled crankshaft is the best and only way to install multiple bearings close to the cams. Even though there is minimal flexure in this design, spherical bearings eliminate stress concentration or point loading. With cam to bearing distances no more than 10 in, the bending moment on a quadraplex crankshaft will be one quarter that of the triplex or five cylinder pump.

In an environment where few advances have been made in mud pump technology in the last 50 years, designers in the mud pump sector of the drilling industry can develop workable solutions to the problems and limitations inherent in triplex pumps.

The future of mud pump design will involve a solution to excessive crankshaft bending moments and address other needed areas of improvement, including piston speed, module replacement in the field, quality of discharge pressure and smoothness of flow-all combined with ease of transportation.

Are you going to be using a pressure washer for high-pressure applications? Blasting oil and fats off concrete or brick walls? Removing graffiti from the outside of your building? Cleaning your industrial machinery?

Or maybe you’re going to be using a pressure washer for lower-pressure applications? Washing the sides of your house? Washing the family car? Washing the mud off your kids in the backyard—okay, that one is probably a criminal act, so don’t do it. Soft washing your roof?

Different types of pumps have different applications they work best for. The text below describes the differences and similarities between types of pumps, and the different applications each is best suited for.

For the most part, these two types of pumps function the same way. Both are reciprocating positive displacement pumps which pull water through an intake valve and into a chamber and push it—pressurized—back out through an outflow valve. These valves are engineered to be one-way only, meaning the intake valve will only open under negative pressure and the outflow valve will only open under positive pressure.

Duplex pumps have two pistons or plungers while triplex pumps contain three. This means duplex pumps must move faster to generate the same pressure levels as triplex pumps, consequently wearing their parts faster, and often causing a pulsating effect.

Triplex pumps last longer because each individual component has to do less work. Furthermore, the flow of water from triplex pumps is more constant, lessening the components’ strain even more.

Plunger pumps use a reciprocating plunger to pressurize water and force it through the outlet valve. The plunger is normally made out of hard ceramic, which is very durable and resistant to wear.

The plunger is attached via connecting rod to a rotor. As the ceramic plunger reciprocates out, it creates suction pressure drawing fluid through the intake. As the rotor turns, the plunger is pushed back down to send fluid through the outflow valve.

Similar to plunger pumps, piston pumps use reciprocating pistons to pressurize water and force it through the outlet valve. The difference between a piston and plunger pumps is the high-pressure seal. In a piston pump, the seal is attached to and reciprocates along with the piston.

Because of this, piston pump seals wear out faster and cannot handle as much pressure compared to plunger pumps. As the seal wears out, the power washer will suffer from reduced pressure buildup, resulting in a weakened stream and inefficient operation.

Pump failure is rarely the cause of power washer problems. The leading causes of pressure washer problems are system restrictions, which cause the pump to fail.

If the inlet hose or valve is not getting enough water to the pump, air is sucked in—this is called cavitation. When this mixture of water and air bubbles is pressurized it creates small explosions, damaging the pump and its components.

The easiest way to combat cavitation is to install a quality inlet valve and filter. This is especially true if the inlet source is a water tank, where many larger particles may sit and settle. If you are using particulates, such as sand, to assist with surface cleaning, make sure to use an appropriately-sized filter mesh to prevent clogging; you must also make sure your pressure washer has enough power to make sure the sand does not wash back into the machine, whereby ruining the pump.

Taken care of properly, with regular maintenance checkups, your pressure washer pump should last at least as long as the hour-rating it’s supposed to last for as per the owner’s manual. As we’ve said, actual pump failure is rarely the cause of the problem, but rather the result. Give us a call or submit a contact form with your questions, and we’ll do our very best to give you the right answer.

Centerline Manufacturing is committed to the highest level of customer service quality.  Every Centerline pump is comprehensively and repeatedly tested at diverse pressure levels to assure that it goes to our customer in perfect operational order. Centerline technicians work to ensure that our customers fully understand the operation of the model being delivered.  If a customer"s pump is down, we understand the importance of timely response and parts availability.  Centerline technicians will assess the problem and make repairs to bring the pump back into new specification. The Centerline mud pump technicians are well versed and qualified to operate and repair any product that is provided to the customer.

Mud Pumps come in both electric and gas / diesel engine drive along with air motors. Most of these pumps for mud, trash and sludge or other high solids content liquid dewatering, honey wagon and pumper trucks. Slurry and mud pumps are often diaphragm type pumps but also include centrifugal trash and submersible non-clog styles.

WARNING: Do not use in explosive atmosphere or for pumping volatile flammable liquids. Do not throttle or restrict the discharge. Recommend short lengths of discharge hose since a diaphragm mud pump is a positive displacement type and they are not built with relief valves.

The article presents selected technical issues relating to drilling performed by a drillship, one type of drilling rigs. Basic problems encountered in the main function of such rigs − drilling a well − are failures of mud pumps. The authors investigate these pumps in operational conditions, aiming at development of a system for monitoring the technical condition of these pumps. Work on a diagnostic system is in progress that will permit to predict the condition of mud pump valves well in…Expand