RU2199009C2 - Device and method of well hydrodynamic investigations and tests - Google Patents

Abstract

FIELD: oil producing industry. SUBSTANCE: method includes determination of quantitative values of formation parameters and taking of sealed samples of fluid with provision of control over entire test cycle by recorded pressure diagrams which serve as a base for calculation of producing formation hydrodynamic parameters. Run into well for the purpose on logging cable is device with remote control of processes of packer setting, fluid inflow restoration of pressure in underpacker or interpacker zone and subsequent automatic removal of packers. To attain said technical result, use is made of device which consists of packering unit with rubber members, depression chamber for induction of fluid inflow from formation and consisting of set of tubing pipes with valve system, atmospheric pressure, sealed sampler and remote pressure pickups for control over entire process of hydrodynamic tests - opening of receiving valve, fluid inflow and restoration of pressure in underpacker or in interpacker zone with recording of pressure diagrams for calculation of all hydrodynamic parameters of producing formation. In so doing, used for device running into well is a logging cable and for packer setting, control of valve system of depression chamber and automatic removal of packers, use is made of one of electrohydromechanical drive ensuring opening of depression chamber after packering of tester only. Rubber members of packering unit are cylindrical and spaced from one another at a distance from 2-3 cm to several meters. The distance between packers amounting up to several meters is used for hydrodynamic testing with single-packer assembly, with two packering members or selective tests with two-packer assembly. In this case, made on external surface of rubber members are concentric bores for production of hydroseal of high-pressure zones on contact of packer with pipe string. Said zones are formed in mechanical compression of rubber members to provide for airtightness of packering. Depression chamber is made with total volume of up to 300 l. EFFECT: higher efficiency of operating wells due to provision of multifunctional complex for well hydrodynamic investigation and testing on logging cable. 2 cl, 6 dwg

Description

 The invention relates to the oil industry and can be used to increase the efficiency of wells.

 In the process of developing oil fields, it is extremely important to evaluate the effectiveness of the secondary opening of productive formations after casing and perforation, testing of productive formations to determine hydrodynamic parameters, production rate, impact on productive formations with cleaning of the near-wellbore area to enhance oil inflow, assessing the tightness of the production string and others. The solution of these problems by traditional methods requires a lot of time and considerable labor costs.

 In most cases, this problem is solved by devices lowered into the well on a string of tubing (tubing). (See A.S. 968349 and 1481385).

 The disadvantage of such devices is the low reliability and high complexity of tripping, wear of the locking sleeves in an abrasive environment, a small flow of fluid.

 A sufficiently close analogue of the proposed technical solution is a device for cleaning the near-wellbore zone of productive formations (AS 874964, MKI E 21 V 21/100, 1981, Almetyevskoye OGPD), which contains a control unit with a cable lug mounted on a geophysical cable and connected to Depression and process chambers, a check valve installed in the vertical channel of the housing connected to the depression chamber, and a spool valve blocking the radial openings. The locking mechanism is equipped with a fusible plug. The disadvantage of this device is the small volume of the depression chamber, the inability to repeat work without lifting the tool and the lack of express information.

 The closest technical solution is the "Device and method for hydrodynamic research and testing of wells (5) according to the application 96112275.

 It consists of: "a packing device with rubber elements, a depression chamber for creating fluid flow from the formation, consisting of a set of tubing with a valve system with atmospheric pressure, a sealed sampler and remote pressure sensors to monitor the entire process of hydrodynamic testing - opening the receiving valve, fluid flow and pressure recovery in the sub-packer or interpacker zone with registration of pressure diagrams to calculate all the hydrodynamic parameters of the product The leg seams.

 The essence of the method: "determining the quantitative values of the parameters of the reservoir and the selection of sealed fluid samples, ensuring control of the entire test cycle according to the recorded pressure diagrams, which calculate all the hydrodynamic parameters of the reservoir".

 The disadvantage of this device is the inability to repeat the work, the impossibility of interval testing of the column from top to bottom and from bottom to top, the lack of express information about the result of the test and exposure.

 The objective of the invention is to obtain a technical result.

 EFFECT: multifunctional technological complex for hydrodynamic research and well testing (MTK GDI) on cable.

Tasks to be solved:
1. Interval pressure testing of the production casing.

 2. The multi-cycle depressive and repression effect on the treated formations with the cleaning of the bottom-hole zone with the extraction of the cleaning products to the surface.

 3. Cleaning the bottom of the well with the extraction of sediment and metal objects to the surface.

 4. Testing of productive formations with a one-packer arrangement of equipment with registration of HPC and the issuance of all hydrodynamic parameters and the selection of sealed samples.

 5. Selective testing of formations in a two-packer arrangement of equipment with the registration of HPC, the selection of pressurized samples and the issuance of all hydrodynamic parameters.

 6. Rapid assessment of the technological effectiveness of various methods used to increase oil recovery or enhance oil flow from the reservoir.

 7. Certification of a productive object in order to assess the excellence of its hydrodynamic opening before putting it into operation.

 This technical result is achieved by the fact that a device for hydrodynamic research and testing of wells is proposed, consisting of a packing device with rubber elements, a depression chamber for creating fluid flow from the formation, consisting of a set of tubing with a valve system, atmospheric pressure, a sealed sampler and remote pressure sensors for monitoring the entire process of hydrodynamic testing - opening the inlet valve, fluid flow and pressure recovery in one-packer or interpacker zone with registration of pressure diagrams for calculating all the hydrodynamic parameters of the reservoir, characterized in that a geophysical cable is used to lower the device into the well, and one electro-mechanical-mechanical drive is used for packing, controlling the valve system of the depression chamber and automatic unpacking, which opens the depression chamber only after packing the tester, while the rubber elements of the packing device are cylindrical and can positions between each other at different distances, from 2-3 cm to several meters, to ensure hydrodynamic tests in a single-pack arrangement with two packer elements or selective tests with a two-pack arrangement with a distance between packers of several meters, while concentric on the outer surfaces of the rubber elements Grooves for creating at the contact of the packer with the column of high-pressure hydrothermal zones formed during mechanical compression of rubber elements, providing sealing NOSTA packer and depressional chamber is configured with a total volume of 300 liters.

 The electro-hydromechanical drive is located in a closed hydraulic system, hydrodynamically balanced with hydrostatic pressure in the well using a pressure compensator. Hydrodynamic balance of the hydraulic system allows automatic unpacking in an emergency - power outage, failure of the electric motor or hydraulic pump due to pressure equalization in the power cylinder under the piston rod, returning it to its original (transport) position. To provide a mechanical force of more than 7.0 tons for compressing the rubber elements of the packer system, the diameter of the power piston is more than 2.5 times the diameter of the rod, while the rod is hollow, which allows for a single-pack arrangement to control the pressure in the sub-packer zone with a sensor located above the power cylinder, and with a two-packer arrangement, the placement at the ends of its two chambers with atmospheric pressure made it possible to create a hydraulically balanced receiving valve with its location between the packing elements. The applied technical solutions for the design of the power piston-rod, the closed hydraulic system of the electro-hydromechanical drive, hydrodynamically balanced with the hydrostatic pressure in the well, the use of two chambers with atmospheric pressure and the hydraulically balanced receiving valve with the location between the packing elements in the two-packer arrangement made it possible to create an optimized device design with wide functional capabilities hydrodynamic studies of wells with emergency response protection.

 A method for hydrodynamic studies of reservoirs is also proposed with quantitative determination of reservoir parameters and sealed fluid sampling.

 The essence of the method is that a well with a geophysical cable is lowered by a test device with remote control of the processes of packing, fluid inflow, pressure restoration in the sub-packer or inter-packer zone and the subsequent unpacking with ensuring control of the entire test cycle according to the recorded pressure diagrams using the device proposed above .

 A device for hydrodynamic research and well testing lowered on a geophysical cable is shown in FIG. 1. It consists of a housing 4, in which an electric motor 5 with a high pressure hydraulic pump 6 is located, having hydraulic communication channels 8, 10 with a cylinder, in which there is a power piston rod 11. In the upper part of the housing there is an external pressure compensator with a piston 3 and a pressure sensor 36. In the lower part of the housing there is a packer assembly consisting of two rubber elements 14, three movable couplings 13 connected to the power piston rod using pins 15. The housing 4 of the packer assembly is connected to the housing 20 of the depression chamber, the upper part of which the valve 16 of the launch chamber 17 is located, the valve-load 19 held by the rod 18. In the lower part of the depression chamber there is a receiving valve 21 fixed by the rod 22 with receiving channels 23. In the shank of the depression chamber there is an autonomous pressure gauge 25, a sampler 26 for sampling sealed samples and trap 24 for the receiving valve 21. In addition to the stand-alone manometer, a pressure sensor 9 is used to monitor and record the pressure in the sub-packer zone. To control the pressure generated by the pump, valve 7 is provided. The device is lowered into the well on a geophysical cable 1 connected to the device using a cable head 2.

 The design of the packer assembly is such that the rubber packer elements 14 can be mounted in close proximity as shown in FIG. 1 for a single-packer arrangement, or at a distance from each other for a two-packer arrangement, as shown in FIG. 4 for selective testing of individual layers, the distance between the rubber elements can be adjusted in the required sizes using hermetically connected pipes to extend the lower part of the housing 4 and the stem of the power piston 11. With a two-packer arrangement, a receiving valve with receiving channels 33 and 34 of the depression chamber is located between the rubber packer elements.

 The remaining notation is as follows; 27 - elongated sleeve, 28 - depression chamber, 29 - column, 30 - cement, 31 - rock, 32 - layer, 35 - elongated rod. 12 - channel of the rod of the power piston.

 The device operates as follows.

 When applying electric current through the geophysical cable, the electric motor 5 starts and at the same time the hydraulic pump 6 starts to work, pumping transformer oil through channel 8 into the sub-piston zone. With increasing pressure, the piston 11 moves upward and with the help of the rod, pins 15 and movable sleeves 13 compresses the rubber elements 14, ensuring the packaging of the device. As the rod moves up, the valve 16 of the launch chamber 17 opens, as a result of which the rod 18 is cut off under the action of hydrostatic pressure and, under the action of the supply valve-cargo 19, the intake valve 21 opens, providing fluid access from the well into the depression chamber, creating a sharp depression on the formation. Under the influence of depression, fluid flows from the formation, cleaning the pores of the near-wellbore zone of the formation (PZP). The inflowing liquid enters the depression chamber and sampler 26. After the completion of the flow of fluid from the reservoir, the device continues to be held in a sealed state until the pressure and the under-packer zone are completely restored, while the pressure change dynamics sensor 9 is monitored and the pressure recovery curve is recorded, according to which hydrodynamic parameters of the reservoir. Registration of the HPC is duplicated by an autonomous pressure gauge 25. After the pressure recovery process is completed, the device is unpacked by turning off the electric motor, while the power piston returns to its original position, and the device is removed to the surface.

 The hydrodynamic research method for interval testing the production casing with the aim of finding failure intervals using the proposed packer is shown in FIG. 3. The technology of interval testing the production casing to localize the intervals of violations is performed without a depression chamber, while the pressure above the packer and under it is controlled by sensors 9 and 36, according to the readings of which the interval of violation of the production casing is set. The pressure in the overpacker zone of the well is created using a hydraulic unit located on the surface.

 The proposed method is a direct method for studying the technical condition of the production casing and is more effective in comparison with the geophysical methods used for this purpose, especially when examining the upper part of the casing where geophysical methods are not effective.

 A method for hydrodynamic testing of wells in a single-pack arrangement is shown in FIG. 2. The device is lowered into the well on a geophysical cable and installed so that the receiving channels 23 of the depression chamber are located against the test formation.

 After that, the device is packaged, depression is created and the HPC is recorded. After the registration of the HPC, the device is unpacked and together with the fluid from the reservoir rises to the surface.

 The method for cleaning the bottom of the well using the proposed device is illustrated in FIG. 6. To clean the bottom of the device, the device is used without rubber elements, while the depression chamber is equipped with a check valve, and a shank with an open end part is screwed onto the bottom of the case of the depression chamber to direct the fluid flow into the depression chamber from the bottomhole zone of the well. A trap is installed in the lower part of the shank to hold metal objects carried away by the fluid flow.

 For cleaning, the device is lowered into the well and installed on the bottom. By turning on the electro-hydromechanical drive, the valve system of the depression chamber opens, and the fluid flow, under the influence of hydrostatic pressure through the liner, rushes into the depression chamber, entraining sediment and sediment from the bottom. After filling the depression chamber, the device rises to the surface.

 The process of selective testing of one formation is shown in FIG. 5. Depending on the thickness of the formation, the distance between the rubber elements and the volume of the depression chamber are determined, the device is assembled and lowered into the well. Upon reaching the study interval, the packing process and the opening of the depression chamber are controlled from the surface. Under the influence of a sharp depression, an intensive flow of fluid occurs with the cleaning of the near-wellbore zone of the formation (PZP). Then there is the process of pressure recovery and the HPC is recorded. After which the device is removed to the surface.

 The use of a single hydromechanical drive for packing, controlling the valve system and unpacking provides consistent control of the entire process of hydrodynamic research and testing of reservoirs.

 The implementation of the depression chamber from the tubing set makes it possible to increase its volume to the required size, while the overall design allows you to place a pressure sensor with data transmission to the surface - this allows you to get express information about the hydrodynamic properties of the formation by registering the pressure-drop coefficient on the surface. Packing quality is controlled by a sub-packer pressure sensor. The same sensor evaluates the tightness of the production string.

 The use of two rubber elements with the possibility of location at different distances between each other allows for single-pack and two-pack layout of the device.

 The hydrodynamic balance of the electromechanical actuator in combination with a valve system in the form of a hollow stem of a power piston, a load valve and a receiving valve of a depression chamber balanced by atmospheric and hydrostatic pressure in the well, allows providing emergency protection multifunctional capabilities of the device for solving complex technical and technological problems of hydrodynamic research and testing of wells on a geophysical cable.

Sources of information
1. Copyright certificate 968349.

 2. Author's certificate 874964, MKI E 21 B 21/00, 1981

 4. Patent 2123577, MKI E 21 B 37/100, 43/18, 34/06, 1998, bull. 35, authors: Korzhenevsky A.G. and etc.

 5.Application 96112275 A, class E21B49 / 00, 03.20.1999

Claims (2)

 1. A device for hydrodynamic research and testing of wells, consisting of a packing device with rubber elements, a depression chamber for creating a fluid inflow from the formation consisting of a set of tubing with a valve system, atmospheric pressure, a sealed sampler and remote pressure sensors to monitor the entire process hydrodynamic tests - opening the receiving valve, fluid inflow and pressure restoration in the sub-packer or interpacker zone with registration of pressure charts A system for calculating all the hydrodynamic parameters of the reservoir, characterized in that a geophysical cable was used to lower the device into the well, and one electrohydromechanical drive was used for packing, controlling the valve system of the depression chamber and automatic unpacking, which ensures that the depression chamber is opened only after packing the tester. the rubber elements of the packer are cylindrical and can be arranged between each other at different distances, from 2-3 cm to sharp meters to ensure hydrodynamic tests in a one-packer arrangement with two packer elements or selective tests with a two-packer arrangement with a distance between packers up to several meters, while concentric grooves are made on the outer surfaces of the rubber elements to create increased pressure zones on the contact of the packer, formed during mechanical compression of rubber elements, ensuring the tightness of the packer, and the depression chamber is made with a common up to 300 liters.  2. The method of hydrodynamic research and testing of wells with the determination of quantitative values of the parameters of the reservoir and the selection of sealed fluid samples to ensure control of the entire test cycle by the recorded pressure diagrams, which are used to calculate all the hydrodynamic parameters of the reservoir, characterized in that the device is lowered into the well on a geophysical cable with remote control of the processes of packing, fluid influx, pressure recovery in the sub-packer or inter-packer zone and subsequent via-automatic packer releasing device according to claim 1.

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