Why should the drilling pump change the cylinder liner when drilling when changing 5

First of all, when the cylinder liner is damaged, it needs to be replaced, which is a must.

Secondly, according to the different downhole conditions, we need to adjust the displacement of the drilling fluid, the speed of the non-electric pump is due to the speed of the diesel engine is constant, and the piston stroke of the pump is also certain, so to adjust the displacement, only replace the cylinder liner and change the cross-sectional area of the cylinder.

Of course, the speed of the electric drilling rig or electric pump can be easily adjusted by the motor, so in addition to the damage of the cylinder liner, there is no need to change the cylinder liner.

The cylinder liner is a consumable part, that is, a consumable, so it is normal and necessary to change the cylinder liner.

Why do you need to change the cylinder liner?

1. Because the drilling mud contains a large number of cuttings, the cuttings will grind and mill the inner wall of the cylinder liner during the use of the cylinder liner, resulting in the inner diameter of the cylinder liner becoming smaller or pitting and puncture leakage, and the liquid supply capacity and pressure supply capacity will be reduced at the same time, and even the water hose will jump due to uneven pressure, which will cause harm to the drilling floor staff.

2. Due to the fact that in the drilling process, the copper sleeve is replaced according to the different well depths, different drilling formations, different drilling methods (underbalanced drilling, balanced drilling, high-pressure jet drilling, etc.), the matching of the drill bit waterhole, and the handling of downhole accidents.

3. The demand for pump pressure and displacement is different.

When will it be replaced?

1. According to the requirements of drilling technicians, replace according to the parameters such as diesel engine speed, required pump pressure and displacement, and specific gravity of drilling fluid.

2. When there is a problem with the cylinder liner, it should be replaced in time (the deputy driller must be well checked and optimistic about the pump).

3. When special operations are required.

Because there are a lot of sediment substances in the drilling fluid, it will cause certain wear to the cylinder liner, and the displacement and pump pressure of the mud pump will not reach a standard after the cylinder liner is worn, which has a great impact on the drilling quality and progress. Therefore, it is necessary to check and replace the cylinder liner in time.

When the drilling pump leaks slurry and there is abnormal sound.

In addition to the damage of the cylinder liner, there is also when you need to adjust the pump pressure during drilling, with the increase of the well depth or the replacement of the drilling tool (that is, the change of the inner diameter will affect the pump pressure), the pump pressure can not meet the construction needs, and the size of the cylinder liner displacement can affect the pump pressure.

Because the maximum working pressure produced by the cylinder liner of different diameters is different, with the increase of well depth, the change of wellbore size, and the change of mud gravity, it is necessary to comprehensively consider replacing the cylinder liner, and at the same time, it is necessary to take into account the displacement.

First of all, the drilling pressure is mainly based on the actual needs of the site, generally with the drill bit used, the speed of drilling, and real-time working conditions, such as directional drilling or directional drilling, whether there is friction resistance or not to support pressure and other factors to determine, and the drilling pressure can also have an impact on the well oblique penetration rate, so these are more practical experience. As for the pump pressure, it seems that there is no selection, it is the pressure loss of the mud from the circulation process. Pumps have their own rated power, will also have their own can withstand the maximum pump pressure is generally about 22MPa, you have to determine whether these pressure consumption will exceed your maximum pump pressure ()22MPa) in the on-site construction with the increase of well depth, try to ensure that their drilling tools will not produce too much pressure consumption. Is it true that the lower the pump pressure, the better, and no. For the selection of the cylinder liner, first of all, we must look at the size of the wellbore, so as to know the required displacement, large displacement with large cylinder liner, small displacement can choose the cylinder liner of the small shop, but if the conditions are limited, you can adjust the displacement by adjusting the speed of the diesel engine and then adjusting the pump punch, which can make the small cylinder liner have a larger displacement, and the large cylinder liner can also achieve a small displacement by reducing the pump punch, of course, I am talking about the mechanical pump, as for the electric pump, the adjustment will be very flexible.

The on-site work has the corresponding displacement of the cylinder liner and the pump flush, and the size of the corresponding cylinder liner should be determined according to the actual situation of the site.

If the whole drilling construction process is compared to the human life activity, then the drilling pump, like the human heart, is the source of the continuous circulation of drilling fluid from the ground to the bottom of the well, and then from the bottom of the well back to the surface. The drilling pump sucks the drilling fluid in the circulating tank, and at a pressure of 10 30 megapascals and a conveying displacement of 20 60 liters per second, it passes through the high-pressure manifold, water hose, drill pipe, and drill bit nozzle on the ground to the bottom of the well, and will also form a high-pressure jet when flowing through the drill bit nozzle, which plays the role of breaking rocks, cleaning the bottom of the well, and cooling the drill bit. When drilling with a bottomhole screw or turbine drilling tool, the drilling fluid is the power source of the power drilling tool.

In the process of drilling, if the drilling pump can not work normally, the drilling fluid can not maintain the circulation, there will be a downhole drilling engineering accident, just like the human heart stopped beating.

Reciprocating pump is a kind of drilling pump commonly used in oil drilling rigs, its principle of action is exactly the same as that of the general reciprocating pump, the power end of the drilling pump is a group of cranks, slider mechanism, because the liquid transported is mostly mud, so it is also called mud pump. There are many kinds of classification of drilling pumps, which can be divided into double-cylinder pumps and three-cylinder pumps according to the number of cylinders of the pump; According to the number of times the piston reciprocates the inhalation or discharge of liquid, it can be divided into single-acting pump and double-acting pump. At present, in the oil drilling rigs at home and abroad, the most widely used are double-cylinder double-acting and three-cylinder single-acting piston drilling pumps.

The efficiency of the drilling pump directly affects the speed and process of drilling, the pump valve, piston, cylinder liner and sealing elements of the drilling pump, because of the long-term work in the drilling fluid containing fine sand, the working environment and conditions are very harsh, is the weakest part of the drilling pump accessories. In recent years, with the joint efforts of scientific research and manufacturing units, China has developed a number of high-quality and long-life drilling pump accessories, which has greatly improved the work efficiency of drilling pumps.

Oil drilling rig drilling pump in the 80s of the 20th century, due to the rise and development of jet drilling technology, the matching and updating speed of high-horsepower drilling pump has been greatly accelerated, it only took more than ten years, the mud pump has been increased from the past 600 horsepower, to the current horsepower, individual deep well drilling team is also equipped with 1600 horsepower drilling pump.

They are all three-cylinder, and there are many cylinder liner sizes, etc., mainly using 170mm and 130mm. Now the cylinder liner is still ceramic. It is rarely used in China.

3 cylinders, the inner diameter is usually 170, when using drill pipe, usually use 130 cylinder liners. There are also 160's.

The purpose and practice of low pump impulse test:

1. Purpose. The pump pressure of the kill displacement is obtained to facilitate the calculation of the kill parameters. Such as initial pump pressure, final pump pressure, etc.

2. Methodology. The kill displacement is generally 1 2-1 3 of normal drilling. For the sake of simplicity, to single or reduce the diesel engine throttle to 800 rpm cycle, record the pump pressure at that time, generally speaking, replace the drilling tool structure, mud performance changes and other situations should do a low pump punch test, according to the team generally once per shift, of course, it is not necessary to do non-drilling during the drilling, casing, electrical measurement, etc.

When killing the well, it is necessary to use a small displacement to kill the well, as long as the drilling fluid is circulated, there will be circulating pressure loss. Due to the high vertical pressure after the overflow, coupled with the circulating pressure consumption, it is likely to be beyond the tolerance of the pump. For example, the vertical pressure after shutting in is 15MPa.

The pump pressure is 15MPa during the normal displacement cycle. In this way, it adds up to 30MPa, and the pipeline may be punctured. The purpose of doing a low pump impulse test when drilling:

Parameters are provided for the calculation of "initial circulating pressure" and "final circulating pressure" when killing wells. Among them, the initial circulating pressure = shut-in vertical pressure + low pump punch test pump pressure + additional safety pressure at the bottom of the well, and the final circulating pressure = low pump punch test pump pressure * kill fluid density Drilling fluid density in the drill string. At the same time, because the displacement used when killing the well is the displacement when doing the low pump punching test, so that the control of the kill process and the progress of the kill and the judgment of the kill effect can be made through the change of riser pressure when the well is killed.

The purpose of the low pump punch test during drilling is to provide parameters for calculating the initial circulating riser pressure and the final cycle vertical pressure when killing the well, because the total pressure of the initial circulating riser = vertical pressure + low pump punch test pump pressure + additional safety pressure at the bottom of the well, and the final cycle pressure = low pump punch test pump pressure * kill fluid density Mud density during drilling. At the same time, because the displacement used when killing the well is the displacement when doing the low pump punching test, so that the control of the kill process and the progress of the kill and the judgment of the kill effect can be made through the change of riser pressure when the well is killed.

Generally, it is required to do a low pump impulse test about 100m before entering the oil and gas layer, before each new drill bit starts drilling, the mud performance changes greatly, every 200m drilled and the pump replaces the cylinder liner. Specific method: open the pump with 1 2 1 3 displacement of normal displacement during normal drilling, and record parameters such as pump flushing, displacement, pump pressure and diesel engine revolution.