RU2720727C1 - Method for determination of tightness of downhole equipment for simultaneous separate operation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and can be used for determination of tightness at simultaneous separate operation of production wells. Method includes installation of packer between productive formations by means of process pipes, which after installation are removed from well, disconnecting from disconnector, lowering on electric-centrifugal pump centrifugal pump string with switch, nipple part and check valve and connection with packer disconnector for communication with under-packer space, lowering plug-in rod well pump into tubing string before installation in switchboard for communication with above-packer well space, checking equipment for tightness. First, all pipes and equipment are pressurized at special test benches with inspection of quality of connecting units and threads. After the packer is installed in the process string, the pressure required for pressing is created with control of fluid discharge from the well and pressure drop inside with further disconnection from the packer. Before the nipple part is lowered to the well, a check valve is installed from below, before the electric centrifugal pump assembly during descent into the well excessive pressure is created inside the nipple part by monitoring the well spout and the pressure drop inside. After the plug-in pump is installed in the switch in the tubing string excessive pressure is created, the pressure required for pressure testing is created with control of the liquid discharge from the well and pressure drop inside. At permissible parameters of tightness during successive check at each stage conclusion is made on tightness of all downhole equipment.

EFFECT: technical result consists in reliability and simplicity of determination of tightness of downhole equipment with simultaneous separate operation, with possibility of tightness control directly during installation of equipment in well or replacement with simple and approved methods without using special equipment, which ensures tightness of equipment after installation and during prolonged operation.

1 cl, 1 dwg

Description

The invention relates to the oil and gas industry and can be used to determine tightness during simultaneous and separate operation of production wells.

A known method of simultaneous and separate operation of a well of multilayer deposits (patent RU No. 2380526, IPC ЕВВ 43/14, published on January 27, 2010 in Bull. No. 3), which includes descent into a well with several layers, at least on one pipe string, without or with a muffled lower end of at least mechanical, impulse, support, hydraulic, hydromechanical or electrical packers, without or with a pipe string disconnector, wherein the packers consist of at least a body, a barrel and a set of cuffs, a packer is installed between at least two bottom-hole zones of formations with low reservoir pressures, without or with a hydraulic anchor, made with two sets of cuffs, between which circulating channels are made on the trunk and a support sleeve with bypass channels is placed on it, after which the packer is planted between the bottom-hole zones of the seams, check its tightness by supplying fluid between two sets of cuffs through the circulation and per Sluice channels of the barrel and support sleeve.

The disadvantages of this method are the narrow scope due to the determination of only the tightness of the packer and the lack of verification of the tightness of the equipment during installation of the equipment or during operation.

The closest in technical essence is a method for determining the tightness of downhole equipment during simultaneous and separate production of fluids from a well by a sucker rod and electric centrifugal pump (patent RU No. 2589016, IPC E21B 47/008, E21B 43/14, published on July 10, 2016 in Bull. No. 19 ), consisting in the fact that they determine the dynamic level in the annular space of the upper object, remove the dynamogram of the sucker rod pump, take the operation parameters of the electric centrifugal pump with the telemetric system, take a control sample of the liquid from the flow line for water cut, make sure that the wellhead valves are working and tight, stop the sucker rod pump of the upper object, both in the lower and in the upper position of the ground drive of the sucker rod pump, pressurize the tubing string using an electric centrifugal pump of the lower object with tracking the pressure changes on the buffer when working on a closed valve, stop electric centrifugal pump and monitor the operation of the installation at the control station, in the presence of an alarm “turbine rotation”, make a conclusion about draining the liquid from the tubing string and the leakage of the check valve of the electric centrifugal pump, at the same rate of increase and decrease of pressure on the well buffer in the different positions of the ground drive of the sucker rod pump and the rate of pressure drop within no more than 2 MPa in 15 minutes make a conclusion about the tightness of the switch and the tubing string in the interval from the electric centrifugal pump to the wellhead, with the rate of increase of pressure on the well buffer in the upper position of the ground sucker rod pump drive lower and the rate of fall higher than in the lower position of the sucker rod pump drive, make a conclusion about the leakage of the cuff fastening in the castle support of the switch, if in the upper position of the ground sucker rod pump drive the centrifugal pump does not develop pressure on the borehole buffer, and in the lower one it develops and the liquid level rises in the annulus, we conclude that the cuff of the sucker rod pump comes out of the castle support of the switch, if both in the lower and in the upper position of the ground rod drive depth pump, the rate of pressure drop on the buffer is more than 2 MPa in 15 minutes, then make a conclusion about the leakage of the switch and / or tubing string in the interval from the electric centrifugal pump to the wellhead, start the sucker rod pump and the electric centrifugal pump into operation, without stopping the sucker rod pump the deep pump of the upper object, stop the operation of the electric centrifugal pump of the lower object, immediately after the electric centrifugal pump of the lower object stops, the liquid level in the annulus is monitored, and the pressure change under the packer is periodically recorded according to the readings of the telemetry system on the control panel of the control station’s olera, at a steadily increasing liquid level, they make a conclusion about leakage, and at a constant liquid level they make a conclusion about the tightness of the packer or section of the tubing string from the electric centrifugal pump to the packer.

The disadvantages of this method are the difficulty of implementation due to the need for a large number of complex operations, which can lead to a high probability of errors, the lack of control of the tightness of the equipment when installing it in the well or replacement, which does not guarantee the tightness of the equipment after installation and during long-term operation.

The technical task of the invention is the creation of a method for determining the tightness of downhole equipment for simultaneous and separate operation, simplifying the control that is carried out during installation in the well or replacing it with simple and tested methods without involving special equipment, which guarantees the tightness of the equipment after installation and during long operation.

The technical problem is solved by the method of determining the tightness of downhole equipment for simultaneous and separate operation, including the installation of a packer between productive formations using technological pipes, which after installation are removed from the well, disconnected from the disconnector, the descent on the tubing string of an electric centrifugal pump with a switch, a nipple part and a check valve and connection to the packer disconnector for communication with the under-packer space, the descent of the plug-in sucker rod pump into the tubing string before being installed in the switch for communication with the over-packer space of the well, and the equipment is checked for leaks.

What is new is that all pipes and equipment are pre-tested on specialized stands with quality control of the connecting units and threads, after installing the packer in the process column, the pressure necessary for pressure testing is created with control of the outflow of fluid from the well and pressure drop inside, followed by disconnection from the packer, before by lowering the nipple part into the well, a check valve is installed from below, before installing the electric centrifugal pump, during the descent into the well, create excess pressure inside the nipple part by controlling the outflow from the well and the pressure drop inside, and after installing the plug-in pump in the switch in the tubing string, create excess pressure the pressure creates the pressure necessary for pressure testing with control of the outflow of fluid from the well and pressure drop inside, with acceptable tightness parameters during a sequential check at each stage, a conclusion is made about the tightness of all downhole equipment.

The drawing shows a diagram of the implementation of the method.

Structural elements and process connections that do not affect the operability of the method are not shown or are conventionally shown in the drawing.

The method for determining the tightness of downhole equipment for simultaneous and separate operation includes preliminary pressure testing in an industrial environment of all pipes and equipment at specialized stands with quality control of the connecting units and threads. After the equipment is delivered to the well 1, packer 2 is lowered into it on technological pipes (not shown), which is installed between the upper 3 and lower 4 productive formations. Then, the pressure necessary for crimping the packer 2 is created in the production string with control of the outflow of fluid from the well and pressure drop inside. In the absence of a spill of liquid from the well outside the casing and pressure drop at an acceptable speed (determined empirically), this casing is disconnected from the disconnector 5 of the packer 2. The casing is then removed to the surface. The nipple part 6 is provided with a valve 7 from the bottom and lowered into the well 1. Before mounting the electric centrifugal pump (ESP) 8, an overpressure is created inside the nipple part 6, due to the presence of the valve 7, controlling the outflow from the well 1 and the pressure drop inside. If there is no liquid outflow from the well outside the nipple part 6 and the pressure drops at an acceptable speed (determined empirically), an ESP 8, process pipe 9, commutator 10, and tubing string are connected to the nipple part 6 in series during descent into the well 1 ( Tubing) 11, on which the descent is carried out with the cable 12 of the ЭЦН 8 until the nipple part 6 is sealed to the disconnector 5 to communicate the ЭЦН 8 with the under-packer space 13 of the well 1. Next, the plug-in sucker-rod deep pump (SHG) 14 is further lowered on rods 15 (can made integral or hollow) into the tubing string 11 until the SHGN 14 is sealed in the switch 10 for communication with the over-pack space 16 of the well 1 using the channels 17 of the switch 10. For pressure testing in the tubing string 11 create excess pressure e with control of the outflow of fluid from the well 1 and pressure drops inside. In the absence of a spill of liquid from the well outside the tubing string 11 and pressure drop at an acceptable speed (determined empirically) after sealing the mouth (not shown) of the well 1 for commissioning (operation) of the ESP 8, cable 12 is connected to the electrical control unit (BU - not shown), and rods 15 ШГН 14 - to the wellhead drive (rocking machine, chain drive, hydraulic drive or the like - not shown). To increase the life of the ESP 8, the packer 2 can be equipped with a filter 18 from the bottom. After starting up the ESP 8 and SHGN 14, the products of the lower layer 4 enter the under-packer space 13, from where they are pumped through the ESP 8 and the nipple part 6 to the process pipe 9 and through the string tubing 11 rises to the surface, and the products of the upper layer 3 enter the overpacker space 18 from where, through channels 17 of the switch 10, they are pumped to the surface through the tubing string 11 or through the cavity of the rods 15 using the SHGN 14.

Since during the descent of the downhole equipment into the well 1, pressure testing (tightness test) of all structural elements is carried out before they are put into operation - this guarantees their tightness after installation in the well and during long-term operation. Moreover, all leakage testing is carried out in simple and tested ways without the involvement of special equipment (a pressure gauge and visual observation are enough) - this greatly simplifies, speeds up and, as a result, reduces the cost of this work.

The proposed method for determining the tightness of downhole equipment for simultaneous and separate operation is simple, reliable and cheap, as it allows tightness control to be carried out directly during installation of the equipment in the well or for replacement by simple and tested methods without involving special equipment, which ensures the tightness of the equipment after installation and during long operation.

Claims (1)

A method for determining the tightness of downhole equipment for simultaneous and separate operation, including installing a packer between productive formations using technological pipes, which, after installation, are removed from the well, disconnected from the disconnector, and the descent on the tubing string of an electric centrifugal pump with a switch, a nipple part and a check valve and connecting to a packer disconnector for communicating with the under-packer space, lowering the plug-in sucker rod pump into the tubing string before installing it into the switch for communicating with the over-packer space of the well, checking the equipment for leaks, characterized in that all pipes and equipment are pre-tested on specialized stands with quality control of the connecting units and threads, after installing the packer in the process column, create the pressure necessary for pressure testing with control of the outflow of fluid from the well and pressure drop inside, followed by by disconnecting it from the packer, before lowering the nipple part into the well, a check valve is installed from below, before installing the electric centrifugal pump, during the descent into the well, create overpressure inside the nipple part, controlling the outflow from the well and pressure drop inside, and after installing the plug-in pump in the switch in the column tubing create excess pressure, create the pressure necessary for pressure testing with control of the outflow of fluid from the well and pressure drop inside, with acceptable tightness parameters during a sequential check at each stage, make a conclusion about the tightness of all downhole equipment.

Images