CN1110374A - Underground booster - Google Patents

Abstract

The invention provides a downhole booster. This is a mechanical booster device installed between the drill stile and the drill bit, which can increase the bottom water pressure by more than 10 times without increasing the surface pump pressure. It adopts a volumetric multi-cylinder hydraulic pressure boosting scheme, that is, multiple double-acting piston cylinders are installed at both ends of the reversing mechanism. Parallel connection is adopted, and each piston and plunger are connected in series with a central spindle to form a whole. Each plunger cylinder has an inlet and an outlet, and is equipped with a filling valve and a discharge valve, and the discharge liquid passes through the ring pipe respectively. The road is connected to the dual pressure drill bit. The reversing mechanism is composed of a reversing trigger, a pilot valve, and a main reversing valve. The reversing trigger receives the motion feedback signal of the central spindle, controls the main reversing valve through the pilot valve, and realizes real-time reversing of the hydraulic circuit, so that the main shaft, piston It reciprocates with the plunger, generates high-pressure liquid in the plunger cylinder, and discharges it from the drill bit nozzle through the annular pipeline, and sprints the rock at the bottom of the well to realize high-pressure hydraulic auxiliary rock breaking to increase the drilling speed.

Description

The invention relates to a petroleum drilling equipment, which adopts a volumetric multi-cylinder hydraulic pressure boosting scheme, which can greatly increase the jet pressure at the bottom of the well without increasing the ground pump pressure, cooperate with the drill bit to perform high-pressure hydraulic rock breaking, and increase the drilling speed .

The speed of oil drilling is closely related to the pump pressure of its drilling pump. At present, the working pump pressure of oil drilling pumps in my country can reach 18-20MPa, and the pump power can reach 1300-1600 horsepower, and the pump pressure of foreign drilling pumps can reach 25MPa. Practice has shown that further increasing the pump pressure can greatly increase the drilling speed. If the drilling pump pressure is increased from 18-20MPa to 30MPa for drilling, the drilling speed can be doubled. The ground experiments of Exxon and Reed companies in the United States show that increasing the pressure drop of the drill nozzle to 100MPa can increase the drilling speed by 5-8 times, and the prospect is very attractive. However, from the perspective of equipment, if the drilling pump pressure is greatly increased, not only the drilling pump itself will have insurmountable technical difficulties, but also the ground manifold and drill string system of the pump will not be able to bear it, and the entire drilling equipment transmission system will also be involved. The problem of redesign and development is relatively difficult to realize in terms of current technological conditions.

In 1990, American Grace/Fowdrill Company commercially launched a kind of "high pressure jet assisted drilling system". This system has achieved the effect of increasing the drilling speed by 2-5 times through industrial tests. Provide ultra-high pressure, full well depth transmission" scheme, so the equipment is extremely complex, which contains a lot of high-tech, the price is extremely expensive, and it is difficult to promote. In terms of current conditions, it is difficult for my country to apply it industrially.

The object of the present invention is to provide a downhole booster which can greatly increase the injection pressure at the bottom of the well without increasing the surface pump pressure, so as to increase the drilling speed.

The purpose of the present invention is achieved in that it adopts a volumetric multi-cylinder hydraulic pressure boosting scheme, which consists of multiple power piston cylinders, booster plunger cylinders, reversing mechanisms, annular flow channels and bearing shells, etc., and the power piston cylinders Both the hydraulic circuit and the pressurized plunger cylinder are connected in parallel, and the reversing mechanism is composed of three parts: a reversing trigger, a pilot valve, and a main reversing valve. Both ends of the reversing mechanism are double-acting piston cylinders, and the outer end of the piston cylinder is a pressurized plunger cylinder. A central spindle is used to connect the pistons and plungers in series to form a whole, so that the spindle, piston, and plunger move as a whole. , which becomes the main moving part of the supercharger. There is an opening on the top and bottom of each piston cylinder, which is connected to its respective annular pipeline. There are two openings on the plunger cylinder, and a one-way valve is installed, one of which is a filling valve. The other is the discharge valve. The discharge fluid path of the supercharger is divided into two paths and connected to the drill bit, one path is for cleaning the bottom of the well under normal pressure, and the other path is for ultra-high pressure rock breaking.

The accompanying drawing is a schematic structural view of the downhole supercharger proposed according to the present invention.

In the figure, 1-pressurized plunger cylinder, 2-plunger, 3-filling valve, 4-piston, 5-annular flow passage, 6-central spindle, 7-reversing mechanism, 8-annular flow passage, 9- Piston, 10-infusion valve, 11-discharge valve, 12-discharge valve, 13-inlet pipeline, 14-high pressure discharge pipeline, 15-normal pressure discharge pipeline, 16-plunger, 17-plunger cylinder, 18-high pressure liquid outlet, 19-normal pressure liquid outlet, 20-carrying shell.

The specific structure of the downhole booster proposed according to the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

The accompanying drawings disclose a downhole booster with two double-acting power piston cylinders and two booster plunger cylinders.

This is a mechanical device installed between the drill collar and the drill bit. It has a long cylindrical appearance and various moving parts, fixed parts and pipelines inside. A set of double-cylinder double-acting hydraulic pressure boosting mechanism is installed in a pressure-bearing shell 20, in the middle of which is a reversing mechanism 7, and a double-acting power piston cylinder is respectively installed at both ends, and the two ends of the piston cylinder are pressurized plunger cylinders 1, 17, two pistons 4, 9 and two plungers 2, 16 are connected into a whole with a central main shaft 6 to form the main moving part of the supercharger. The piston 4 divides the upper piston cylinder into upper and lower chambers X, Y, and the piston 9 also divides the lower piston cylinder into upper and lower chambers M, N. The reversing mechanism has four liquid ports, one of which is the pressure mud inlet port, called P port, one is the normal pressure mud discharge port, called O port, and two working ports, called A and B ports. The reversing mechanism 7 has two kinds of stations, one is that the P port communicates with the A port, and the B port communicates with the O port; the other is that the P port communicates with the B port, and the A port communicates with the O port. Reversing trigger control, the upper chamber X of the upper piston cylinder, the upper chamber M of the lower piston cylinder and the inlet of the upper plunger cylinder 1 (filling valve 3) communicate with each other through the annular flow channel 5, and they are connected with the reversing mechanism 7 at the same time A working port (for example, A port is connected, and the lower cavity Y of the upper piston cylinder, the lower cavity N of the lower piston cylinder, and the inlet (filling valve 10) of the lower plunger cylinder 17 communicate with each other through the annular flow channel 8, and they are simultaneously connected with the Another working port (such as port B) of the reversing mechanism 7 is connected.

The working process of the supercharger is as follows: the ground power mud enters from the P port of the reversing mechanism 7 through the pipeline 13, distributes the liquid path through the reversing mechanism 7, flows out from the working port A, and enters the upper piston cylinder. In chamber X, upper chamber M of the lower piston cylinder and upper plunger cylinder 1, the main moving parts go down due to the mud pressure, and the mud in the lower chambers Y and N of the upper and lower piston cylinders is passed through the working port B of the reversing mechanism. The O port is discharged to the normal pressure liquid outlet 19 for cleaning the well bottom. At the same time, as the plunger 16 of the lower plunger cylinder 17 goes down, the liquid in the cylinder 17 is squeezed out of the discharge valve 11, that is, the lower plunger cylinder 17 discharges the ultra-high pressure liquid, and hydraulic rock breaking is realized through the drill nozzle; when the main movement The parts go down to the bottom dead center, the central spindle collides with the reversing trigger, so that the main valve is reversing, and it is in the second position. At this time, the P port of the reversing mechanism communicates with the B port, and the A port communicates with the O port. In reverse, the upper plunger cylinder discharges ultra-high pressure liquid, the lower plunger cylinder fills with liquid, the main moving part moves up to the top dead center, and the central spindle collides with the reversing trigger to realize the reversing of the main valve, and the main moving part goes down again. So repeated, the continuous reciprocating motion of the main moving part is formed, and the continuous pulsating pressurization of part of the fluid (the part of the liquid poured into the plunger cylinder) is realized, so as to achieve the purpose of pulsating to the bottom of the well and hydraulic rock breaking.

The design parameters of this embodiment are: outer diameter: 7", input flow rate: 25-30 liters/second, input fluid pressure (surface pump pressure): 20-25MPa, maximum working well depth: 4000-6000 meters, maximum well depth Maximum boost output pressure: 175MPa, maximum boost output flow: 2.0-2.5 liters/second.

Claims (2)

1, a kind of underground booster, be installed between drill bit and the drill collar, utilize it can be under the situation that does not improve the ground pump pressure, mud pressure is increased to ultrahigh pressure, carry out the shaft bottom hydraulic drilling by bit nozzle, improve rate of penetration, it is characterized in that, adopt positive displacement multicylinder hydraulic supercharging scheme, in the both sides of changement the power piston cylinder is housed, the supercharging plunger case is installed, piston cylinder and plunger case are connected in parallel with annulus line in the outside of piston cylinder, and connect with the branch dosing road of changement respectively, with a central principal axis each piston and plunger are fused, a liquid-inlet and outlet are respectively arranged on the plunger case, and pouring valve and expulsion valve are housed respectively, exhaust port passes through annular pressure duct respectively to the drill bit high pressure nozzle, and the outlet end of changement connects annulus line to drill bit normal pressure nozzle.

2, underground booster according to claim 1, it is characterized in that, said changement is made of commutation trigger, pilot valve, three parts of main reversing valve, and the feedback signal of commutation trigger receiving center motion of main shaft is by the real-time commutation of pilot valve control main reversing valve.

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