RU2366813C1 - Method of testing wells and reservoir survey in process of boring and facility for implementation of this method - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: group of inventions refers to geological survey and oil and gas industry and can be implemented for testing of wells and for reservoir survey in process of boring. The method consists in lowering the facility with upper and lower packers, with a filter, bottomhole apparatus and bearing plate to bottomhole on drill pipes. The facility is equipped with bottomhole electric pump, with a back valve for packer pressure testing located above the filter, and with a flush sub assembled above the back valve. Further, the facility is equipped with a valve installed above the upper packer and communicating space between the upper and lower packers and circular space formed with an open well bore and drill pipes at open packers; the facility is also equipped with a valve of control over the upper inflated packer, and with a valve of control over the lower inflated packer. In the filter there are assembled bottomhole devices connected with rods adjusted in length so, that they can be installed in filters at different depth and with different arrangement. When the facility is lowered to the botttomhole, the filter covers all thickness of the reservoir with the packers. The bottomhole pump creates depression. Information is picked-up along the whole thickness of the reservoir per one trip of the facility; information is transmitted via a cable. Also there are determined degree of reservoir contamination and radius of external boundary of reservoir.

EFFECT: upgraded accuracy of field information on filtration-capacitive characteristics of producing reservoir in process of boring.

2 cl, 1 dwg

Description

The invention relates to the geological exploration and oil and gas industry and can be used for well testing, formation studies during drilling.

There is a known method of hydrodynamic studies in an open bore by modular reservoir testers MTD, which includes cable descent into a borehole with an open bore of a modular dynamic reservoir tester, which allows the following studies: formation pressure measurements, recording pressure drop and pressure recovery curves (Efficiency and Pressure Reduction), sampling formation fluids. [Hassan Akram, Vladislav Ashurov. An overview of hydrodynamic studies of wells in an open and cased hole by modular formation testers on MTD / CHDT cable // Oil and Gas Review, Spring 2004. - P.30-31.]

To implement the known method, a device is used that includes a multi-probe module for measuring pressure with manometers, a two-packer module that uses inflatable packers to isolate the studied interval of the well, a flow control module that controls the flow rate of fluid withdrawal from the reservoir, and a pumping module (submersible pump) that allows for fluid withdrawal from the reservoir, as well as pumping fluid into the reservoir, a multi-instrument module with six selective chambers for sampling representative samples of reservoir fluid [Hassan Akram, Vladislav Av Ashurov. A review of hydrodynamic studies of wells in an open and cased hole by modular formation testers on the MTD / CHDT cable // Oil and Gas Review, Spring 2004. - P.30-31]. Moreover, the possible configuration of the device depends on the specific task.

The disadvantages of the known method and device are as follows. The dimensions of the MTD along the length of the device and the operations that conduct research in an open borehole are limited by the strength of the cable. In addition, it is not possible to install the required number of devices throughout the thickness of the reservoir. Therefore, the well is tested at intervals and over the entire thickness of the formation, while it is not possible to exclude the flow of fluids and filtrates of drilling fluids, which leads to a distortion of the filtration characteristics of the formations when determining the hydrodynamic characteristics of the formation.

A known method of testing wells, formation studies associated with tripping operations of the tool, creating a deep depression on the formation, a multi-cycle call for the influx of formation fluid and taking deep samples with the obligatory registration of pressure and temperature diagrams at the bottom and in the pipes and determining the hydromechanical parameters of the formation [Technical instruction for testing formations with tools on pipes. (RD 153-39.0-062-00) M., 2001].

To implement this method, use a device - a test of reservoirs on pipes (IPT) [Technical instructions for testing reservoirs with tools on pipes. (RD 153-39.0-062-00) M., 2001]. The device layout includes: support shoe or anchor, nozzle with pressure gauge and leveling device, lower packer, filter, nozzle with manometer, upper packer, safe lock, sampler, jasse, nozzle with manometer, formation tester, shut-off valve, circulation valve, drill pipes (BT). At the same time, the configuration of the device’s layout can be different depending on the geological and field tasks, on the conditions in the well being tested: the rock to be discovered, the location of the test formation in the well.

A disadvantage of the known method and device is that the well is tested during drilling while operating at an unsteady filtration mode, which differs significantly from the study in the production casing, which in principle limits the possibilities of this method. At the same time, the device used to test the well during drilling is not sufficiently reliable in operation: leakage of the drill pipe string, tightening of the tool during hoisting operations, leakage of valves and packers, opening of the test valve - all this leads to poor-quality HPC and unsatisfactory test results.

The task to be solved by the claimed method and device is the development of a method and device, the operational capabilities of which ensure the reliable operation of individual parts of the device’s layout during well testing, formation studies during drilling.

The problem is achieved due to the technical result, which consists in improving the quality of field information on the filtration-capacitive properties (FES) of the reservoir immediately after opening during drilling due to the creation of a new device.

The specified technical result in the implementation of the group of inventions on the object - the method is achieved by the fact that the method of testing wells, investigating formations during drilling includes lowering the device with upper and lower packers, a filter, depth gauges and a shoe to the bottom, drilling down the formation, creating a depression on the reservoir, sampling in-depth samples to determine information with mandatory registration of pressure, temperature and determination of the hydrodynamic parameters of the reservoir. When the device is lowered to the bottom, the filter covers the entire thickness of the reservoir with packers. Depression is produced by a deep electric pump. Information is removed over the entire thickness of the formation in one descent-ascent of the device with the transmission of information by cable, and the degree of pollution of the formation and the radius of the power supply circuit are determined.

The specified technical result in the implementation of the group of inventions on the object is a device for testing wells, studying reservoirs during drilling, contains an arrangement installed on drill pipes, consisting of upper and lower packers, depth tools, a filter and a shoe. Additionally, the device is equipped with a deep electric pump to create a depression on the formation, a check valve for crimping the packers located above the filter, a flushing sub located above the check valve, a valve located above the upper packer and connecting the space between the upper and lower packers and the annular space formed by the open trunk wells and drill pipes, with open packers, a control valve for the upper inflatable packer, a control valve for the lower inflatable packer. Depth instruments are located in the filter and are connected by adjustable rods in length so that they can be placed in the filter at different depths and in different layouts.

It is the claimed arrangement of the device during the implementation of the method that improves the completeness and quality of field information due to the ability to cover the entire formation rather than a separate interval of the formation and to carry out lengthy tests, thereby eliminating the flow of fluids and filtrates of drilling fluids in the formation and removing information in the well at intervals and throughout the thickness of the formation in one run of the device, as well as determine the degree of contamination of the formation and the power supply circuit of the formation.

The claimed group of inventions meets the requirement of the unity of inventions, since it forms a single inventive concept, moreover, one of the claimed objects of the group is a device for testing wells, studying reservoirs while drilling is intended to implement another object - the method. At the same time, both objects of the group are aimed at solving the same problems with obtaining a single technical result.

The operation of the method and device for its implementation is illustrated in the drawing, which shows a device for testing wells, reservoir studies during drilling.

A device for testing wells, investigating formations during drilling is installed on BT 1 and contains a flushing sub 2, below which a check valve 3 and a filter 4 are installed. The upper inflatable packer 5 is located in the upper part of the filter 4, and the lower inflatable packer is located in the lower part of the filter 4 a packer 6, which is controlled by a deep electric pump 7 through a pressure line 8, as well as a valve 9 for controlling the upper inflatable packer 5 and valve 10 for controlling the lower inflatable packer 6. As valves 9 and 10 can be, for example ep, solenoid valves used. Pressure line 8 through a valve 11, for example, an electromagnetic one, located above the upper inflatable packer 5, connects the inter-packer space 12 with the annular space 13 formed by the open borehole and BT 1 with the packers 5 and 6 open. Depth devices, which are used as groups of devices, for example: group 14, consisting, for example, of a pressure gauge, a continuity locator, a gamma-ray log tool, a flow meter, a moisture meter; group 15, consisting, for example, of an electronic pressure gauge, a continuity locator, a gamma-ray logging tool, a flow meter and a moisture meter; group 16, consisting, for example, of an electronic pressure gauge, thermometer. The groups of devices 14, 15, 16 are mounted on the suspension 17 inside the filter 4. The groups of devices 14, 15, 16 are connected to each other by means of adjustable rods 18. The groups of devices 14, 15, 16, the deep-well pump 7, valves 9, 10, 11 with the help of an armored multicore cable 19 (hereinafter cable) are connected to a ground station for operational monitoring of the well testing process and remote acquisition and processing of information (not shown). In this case, the cable 19 enters the filter 4 through the cable connector 20. The arrangement of the device with the shoe 21 ends.

The method is as follows.

A device with a flushing sub 2, a check valve 3, a filter 4 and inflatable packers 5 and 6 is lowered to BT 1 into the open hole 22 to the depth of the formation test after opening it with a chisel with emphasis on the bottom shoe 21. Turn on the deep electric pump 7, and formation the liquid through the pressure line 8, the upper and lower valves 9 and 10 is supplied to the upper and lower inflatable packers 5 and 6, creating a pressure of 7 MPa higher than hydrostatic. Next, the device is packaged.

In order to check the tightness of BT 1 and inflatable packers 5 and 6 launched into the well, ground-based pumping units (not shown) create pressure in the annular space 13 formed by the open wellbore 22 and BT 1 with the packers open, 1.5 times the working pressure. In the absence of fluid circulation at the mouth, the tightness of the inflatable packers 5 and 6, as well as BT 1, is determined.

The deep-well electric pump 7 is turned on and formation fluid (formation fluid) is pumped out from the inter-packer space 12, which is supplied through the pressure line 8 and valve 11 to the annular space 13. A depression is created on the formation and a flow of formation fluid is caused. At the same time, information is transmitted from instrument groups 14, 15, 16 to a ground control station via cable 19, and formation fluid is sampled into the samplers of instrument group 15. By stopping the submersible pump 7, close the valve 11 and record the HPC of the formation 23. In this case, the groups of devices 14, 15, 16, sequentially fixed to each other by threaded adjustable rods 18 in the filter 4 in such a way that the gas-oil circuit (GOC) 24 is closed for one descent , the oil-water circuit (WOC) 25 of the formation 23 of the well 22, and not of a certain interval of the formation 23, and due to this, flows of fluid from the filtrates of drilling fluids are excluded.

At the same time, a lot of time passes during the shutdown of the deep-well electric pump 7 and the HPC recording, and to prevent the accidental manifestation of the well 22 in the annular space 13 (for example, grabbing the device during a rock collapse), the well 22 is flushed through the flushing sub 2. When the device is lifted from the well 22 through the flushing sub 2 by backwashing, the formation fluid that has entered the annular space 13 of the well 22 is displaced and dumped into the tank outside the rig.

Consequently, using appropriate geophysical and hydrodynamic studies and deep-sea instruments, they carry out operational control of the test process, measure formation pressure, assess the mobility of the formation fluid, permeability in the near-wellbore zone and select high-quality samples of the formation fluid, determine the reservoir properties, formation properties by efficiency analysis and HPC, the degree of formation pollution and the radius of the reservoir supply circuit.

After registering all the formation test data, the groups of instruments 14, 15, 16 open the valves 9 and 10, the fluid from the upper 5 and lower 6 packers flows along the pressure line 8 through the valve 11 into the annular space 13. Unpack the device, while the working fluid is fed into the internal space of BT 1 with the check valve 3 closed. The working fluid exits through the flushing adapter 2 into the annular space 13, aligning the parameters of the drilling fluid. Next, carry out the lifting of the device to the surface with a continuous topping of the flushing fluid into the annular space 13 of the well 22.

Using the proposed group of inventions will improve the quality of information about reservoir properties in the process of drilling a well and, as a result, significantly improve the quality of formation testing in one descent of a device that overlays the formation.

Claims (2)

1. A method of testing wells, investigating formations during drilling, including launching devices with upper and lower packers, a filter, depth gauges and a shoe to the bottom hole on drill pipes, isolating the formations, creating depression on the formation, and taking depth samples to determine information with mandatory registration diagrams of pressure, temperature, and determining the hydrodynamic parameters of the formation, characterized in that when the device is lowered to the bottom, the filter covers the entire thickness of the formation with packers, depression is performed by deep electric tronasos, information is taken over the entire thickness of the formation in one descent of the device with the transmission of information by cable, while determining the degree of contamination of the formation and the radius of the power circuit of the formation. 2. A device for testing wells, investigating formations during drilling, containing an assembly installed on drill pipes consisting of an upper and lower packer, depth tools, a filter and a shoe, characterized in that it is additionally equipped with a deep electric pump to create a depression on the formation, the inverse a valve for crimping the packers located above the filter, a flushing sub located above the check valve, a valve located above the upper packer and connecting the space between the upper and lower packers and the annular space formed by the open borehole and drill pipes, when the packers are open, the control valve of the upper inflatable packer, the control valve of the lower inflatable packer, while the depth devices connected to the cable are located in the filter and are connected using length-adjustable rods in such a way that they can be placed in the filter at different depths and in different layouts.

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