RU2541982C1 - Method for operating injector with multiple packer assembly - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes running in of the assembly to the well, setting packers and their leak testing, dual injection of working fluid to productive formations. Before running in the production string is gauged by a gage with length from 30 up to 100 m and diameter less than diameter of the production string per 4-6 mm, at that intervals of gage setting and tightening are marked and reasons for tightening are defined. The production string is studied within intervals of packer setting and intervals of the gages setting and tightening. The well is washed by back washing until clean flush fluid is obtained. The assembly is being assembled. Axial packer is used as the lower packer and thrust plate packers are used as the upper packers. A cable is connected to devices and fixed at outer surface of the assembly. The assembly is run in and its hydraulic leak testing is performed. The plug is removed by means of wire-line technique. The assembly is run in to the well to the required depth at tubing string with measuring length and gaging of inner cross-section of the tubing string. Simultaneously the cable is fixed at outer surface and the cable is run in together with the tubing string. Running speed should be maintained at 0.1 m/s at most. The cable tension is controlled during its running in; no jerks and tension release are permitted. When the tubing string is set to power slips the cable should not be trapped by slips, when releasing the tubing string out of power slips pulling depth should be less than 0.25 m. During running-in weight unload of the tubing string should not be more than 2 t and at unplanned setting of the packer in transport position the tubing string is lifted per 2-3 m and the tubing string is run out slowly passing the packer through interval of unplanned setting. The packers are positioned, fitting of the assembly is made to the preset interval by adjustable tubes, the cable is spliced with wellhead devices, chuck and preventer is mounted, hydraulic leak testing is performed for the tubing string. Value of the tubing string lifting with assembly for packers setting is calculated, the required length is determined for cables from the wellhead up to the controller panel, cable excess is cut, cables are bypassed through the cable input, the packers are set by fixating changes in weight of the tubing string, glands of the cable input are sealed off and functional check of the devices is made. The packers are pressed together and set to gas lift mandrels of pressure regulators with unions of the preset diameters or bottomhole pressure gages, at that during operation at working fluid pumping pressure is measured in the tubing string and annular space between formations and opposite each formation. Dependence of pressure in annular space is controlled on changes in injection pressure of the tubing string; overflow availability is monitored from under the packer to behind-the packer space. Fluid flow rate is defined between packers opposite the formations and when pressure occurs in annular space notwithstanding changes in injection pressure then pressure is released through the casing valve.

EFFECT: improved efficiency of multiple packer assembly setting in the well.

5 ex

Description

The invention relates to the oil industry and may find application in the installation and operation of a multi-packer arrangement in a well.

A known method for simultaneous and separate operation of a well of multilayer deposits, which includes lowering into a well with several layers on a pipe string without or with a plugged lower end of at least mechanical, impulse, support, hydraulic, hydromechanical or electrical packers with a pipe string disconnector or without him. In this case, the packer consists of at least a body, a barrel and a set of cuffs. And the pipe string disconnector consists of at least a housing and a barrel, sealed together by sealing elements, and shear screws. In one embodiment, between the two bottom-hole zones of the strata, two packers are placed in any of the combinations and a bypass element in the form of a borehole chamber or pipe or valve with circulation channels is lowered between them. After simultaneous or separate planting of these packers in the well, their tightness is checked by supplying fluid between the packers through the bypass element by creating excessive pressure in the pipe string. When stopping the flow of fluid, if there is a drop in the value of the latter, take the packers between the layers leaking and at the same time lift them from the well. If the overpressure does not fall, the packers are sealed tight and the well is put into operation. In the second embodiment, a packer with two sets of cuffs is installed, between which circulation channels are made on the trunk and a supporting sleeve with bypass channels is placed on it. Leak test fluid is supplied between two sets of cuffs. In a third embodiment, the pipe string disconnector is installed at least above the packer located between the two bottomhole zones of the formations. At the same time, its trunk is made with at least one or two grooves for shear screws and, accordingly, on the housing, two rows of holes with shear screws are provided. When disconnecting the housing from the barrel, two rows of shear screws are cut off sequentially with increasing excess load on the pipe string when the packer or packers are broken (RF patent No. 2380526, publ. 01.27.2010).

Closest to the proposed invention in technical essence is a method of simultaneously-separately and / or alternating operation of several objects of an injection well, according to which at least one pipe string with a constant or variable diameter without or with a plugged end is lowered , with one packer of hydraulic and / or mechanical action, lowered below the upper layer, without or with a column disconnector. Below and above the packer, at least one landing unit in the form of a borehole chamber or a nipple with a removable valve for lowering the working agent through them into the lower and upper layers, landing the packer and crimping it from below and / or above, is lowered. During crimping, the minimum absorption pressure of each formation is determined. The working agent is pumped from the mouth into the cavity of the pipe string at a given pressure, directing it to the upper and / or lower layers through the corresponding removable valves in the landing nodes. The total consumption of the working agent, wellhead pressure and / or temperature in the cavity of the pipe string and the annulus of the well are measured on the surface. The bottomhole pressure of the upper layer, the pressure in the pipe string and the annulus at the depth of the removable valve in the seat assembly above the packer are determined. Find the flow rate of the working agent injected into the upper layer through a removable valve, subtract it from the total and determine the flow rate of the working agent injected into the lower layer. Compare the actual costs of the working agent for the formations with their design values. In this case, when they differ, the wellhead pressure is changed and / or removable valves are removed for one or both layers from the landing nodes using cable technology. Their characteristics and / or parameters are determined and changed. After that, each removable valve is re-installed in the corresponding landing unit using cable technology and the injection of the working agent through them into the corresponding layers is continued (RF patent No. 2253009, publ. 05.27.2005 - prototype).

Known methods have a limited scope because of the complexity of the operation of launching, landing and removing packer equipment from the well. In addition, when operating the layout, there is no information about the reliability of the packers, about flows between packers, there are no measures to reduce the influence of flows on the operation of the layout.

The proposed invention solves the problem of ensuring trouble-free placement of a multi-packer arrangement in the well and ensuring control of the operation of the well.

The problem is solved in that in the method of operating an injection well with a multi-packer arrangement, including launching the assembly into the well, packing packers and their tightness testing, injecting the working agent simultaneously and separately into the productive formations, according to the invention, the production casing is patterned with a template with a length of 30 or more up to 100 m and a diameter smaller than the diameter of the production string by 4-6 mm, in the process of patterning, note the intervals of planting and puffs of the template indicating the magnitude of these values, determined determine the causes of puffs and make decisions about the possibility of working out the wellbore and the possibility of further equipment placement, work out the production casing in the intervals of installation of packers and in the intervals of planting and tightening the template, flush the well with backwash until a clean wash fluid comes out, mount the assembly with a plug at the end, packers , downhole cameras and devices, the axial-action packer is used as the lower packer, the persistent action packers are used as the upper packers, when the cable is connected to the oram, the cable is fixed on the external surface of the assembly, the assembly is lowered into the well near the wellhead with measuring the length and patterning of the internal section of the layout equipment, hydraulic tests of the run-down assembly are carried out for tightness, the plug is removed using cable technology, the assembly is lowered into the well to the required depth on a string of tubing with measuring length and patterning the internal section of the string of tubing, simultaneously mounted on the outside the surface of the cable and lower the cable along with the tubing string, the descent speed can withstand no more than 0.1 m / s, monitor the cable tension during lowering, prevent jerking and weakening the cable tension, when the tubing string fits onto the wedge grip do not allow cable to enter wedges; when the tubing string is released from the wedge grip, the pipe lifting height is chosen to be no more than 0.25 m; during descent, the weight of the tubing string is not allowed to unload more than two tons, and unplanned landing of the packer to bring the packer into transport position raise the tubing string by 2–3 m and slowly lower the string, passing the packer through the unplanned landing interval, bind the packers, adjust the layout to the specified interval with fittings, spliced the cable with wellhead devices , mount the faceplate and preventer, conduct a hydraulic test of the tubing string for leaks, calculate the lift of the tubing string compression pipes with the layout for planting packers, determine the required cable length from the wellhead to the controller panel, cut off excess cable, pass the cables through the cable entry, install the packers, recording changes in the weight of the tubing string, seal the cable glands and perform a functional check devices, compress packers, install pressure regulators with fittings of specified diameters or borehole pressure gauges into the borehole chambers, and during well operation, When the working agent is injected, the pressure in the tubing string and in the annulus between the strata and opposite each formation is measured, the dependence of the pressure in the annulus on the change in the injection pressure in the tubing string, the flow from under the packer to the over packer space are monitored, determine between packers opposite the reservoirs, fluid flow, and when pressure arises in the annulus, regardless of the change in injection pressure, release pressure through the annulus engine.

SUMMARY OF THE INVENTION

When launching an assembly with an axial packer into the well, there is always the danger of premature unplanned packer placement. With unplanned packing of the axial packer, the descent of the layout becomes impossible. Existing technical solutions do not pay attention to this danger. In order to avoid accidents during the descent, a number of activities are carried out, presented below. Before launching, the production casing is patterned with a template with a length of 30 to 100 mi with a diameter smaller than the diameter of the production casing by 4-6 mm. Such a pattern most closely corresponds to the dimensions of the layout parts - packers, which are most susceptible to friction against the well walls. In the process of patterning, note the intervals of planting and puffs of the template indicating the magnitude of these values. They are taken into account to determine the causes of puffs and to decide on the possibility of developing a wellbore and the possibility of further operation of the equipment. The production casing is worked out with a mechanical or hydraulic scraper in the intervals of installation of packers and in the intervals of planting and puffs of the template until the risk of planting and puffs is eliminated. Wash the well with backwash until a clean wash fluid emerges. Mount the assembly with a stopper at the end, packers, borehole chambers and devices. An axial packer is used as the lower packer, persistent packers are used as the upper packers, configured to differently reduce the weight of the column: lower to smaller, upper to larger.

A cable is connected to the devices. The cable is fixed to the outer surface of the layout. The layout is lowered into the well near the wellhead with measuring the length and patterning of the internal section of the layout equipment. Conduct hydraulic tests of a run-down assembly for leaks. Using a cable technique, a cork is removed. The layout is lowered into the well to the required depth on the tubing string with length measurement and patterning of the internal section of the tubing string. At the same time, the cable is attached to the outer surface and the cable is lowered along with the tubing string. The descent speed can withstand no more than 0.1 m / s. They monitor the cable tension during descent, do not allow jerking and loosening the cable tension. When building the tubing string, it is held at the wellhead in wedge grips. When the tubing string is wedged onto the wedge grip, the cable does not enter the wedges, and when the tubing string is released from the wedge grip, the lifting height of the pipe is chosen to be no more than 0.25 m. During the descent, the weight of the tubing string is not allowed to be unloaded. pipes more than 2 tons, and when the packer is unplanned landing to bring the packer into transport position, raise the tubing string by 2-3 m and slowly lower the string, leading the packer through the interval of unplanned landing. Such a speed of descent, the absence of jerking and weakening of the cable tension and the height of the pipe when it is released from the wedge grip, unloading provide the descent of the layout without unplanned landing of packers. Deviations from the declared modes leads to the landing of one or more packers, which is equivalent to an accident at the well.

Bind packers. Fit the layout to a predetermined interval with fittings. Spliced cable with wellhead devices. Mount the faceplate and preventer. Conduct a hydraulic test of the tubing string for leaks. Calculate the magnitude of the rise of the tubing string with the layout for planting packers. Determine the required cable length from the wellhead to the controller panel. Cut off excess cable, pass the cables through the cable entry. Packers are installed, fixing changes in the weight of the tubing string. Close the glands of the cable entry and check the operability of the devices. Compress packers. They install pressure regulators in the borehole chambers with fittings of specified diameters or borehole pressure gauges. A working agent is pumped through the tubing string. When pumping a working agent, the pressure is measured in the tubing string and in the annulus between the layers and opposite each layer. The dependence of the pressure in the annulus on the change in injection pressure in the tubing string is monitored, the flow from under the packer to the overpacker space is determined, and fluid flow is determined between the packers opposite the formations. If pressure arises in the annulus, regardless of the change in the injection pressure, the pressure is vented through the annular valve.

As a result, it is possible to carry out the layout from the mouth to the bottom without unplanned landing of the packer and to ensure control of the operation of the well.

Case Studies

Example 1. Before operating the injection well with a three-packer layout, a 6-inch production casing with an internal diameter of 152 mm is patterned with a 60 m long template and a diameter smaller than the production casing by 5 mm. In the process of patterning, it is noted that in the interval 950-955 m, the template is tightened by 2 tons and in the range of 1245-1249 m, the template fits up to 5 tons. The published tightening and landing follows that the reason is the presence of corrosive deposits. A decision is made on the possibility of developing a wellbore with a mechanical scraper. The production casing is worked out with a mechanical scraper at packer installation intervals and at template landing and puff intervals until the risk of landing and puffs is eliminated. Wash the well with backwash until a clean wash fluid - water.

At the wellhead, the assembly is mounted in the following sequence (from bottom to top): plug with plug, tubing string, sub, pipe, well chamber KT1-60B-21K2, tubing, sub, packer P-UDC-140-50K2 , column disconnector, sub, tubing, KT1-73B borehole, tubing, PNMK-140-35-K2 packer, tubing string, borehole tubing KT1-73B, tubing string, borehole KT1-73B chamber, tubing string b, benchmark, tubing, PNMK-140-35-K2 packer, tubing, KT1-73B borehole, tubing, crimping nipple, sub, tubing string - main elevator.

A cable is connected to the devices. The cable is fixed to the outer surface of the layout. The layout is lowered into the well at 20 m from the wellhead with measuring the length and patterning of the internal section of the layout equipment. The template passes without puffs. Hydraulic tests of the flat layout for tightness are carried out by increasing the water pressure in the layout to 10 MPa. The layout is tight. Using a cable technique, a cork is removed. The layout is lowered into the well to a depth of 1793 m on the tubing string with length measurement and the internal section of the tubing string being gauged. When templating, the template passes without puffs. At the same time, the cable is attached to the outer surface and the cable is lowered along with the tubing string. The descent speed can withstand 0.1 m / s. They monitor the cable tension during descent, do not allow jerking and loosening the cable tension. When the tubing string is wedged onto the wedge grip, the cable does not enter the wedges, and when the tubing string is released from the wedge grip, the pipe lifting height is chosen to be 0.25 m. During the descent, the weight of the tubing string is not allowed to unload more than 2 tons, and with an unplanned landing of the packer to bring the packer into transport position, raise the tubing string by 2.5 m and slowly lower the string, leading the packer through the interval of unplanned landing. Bind packers. Fit the layout to a predetermined interval with fittings. Spliced cable with wellhead devices. Mount the faceplate and preventer. Hydraulic testing of the tubing string is carried out for tightness with a pressure of 10 MPa. The column is tight. Calculate the magnitude of the rise of the tubing string with the layout for planting packers. Determine the required cable length from the wellhead to the controller panel. Cut off excess cable, pass the cables through the cable entry. Install packers. A sharp jerk up the tubing string at a speed of more than 0.1 m / s set the lower axial packer. Then, by unloading the weight of the tubing string by 6 tons, the middle packer is installed and by unloading the weight of the tubing string by 6 tons, the upper packer is installed.

Close the glands of the cable entry and check the operability of the devices. Packers are pressed at a pressure of 10 MPa. Install pressure regulators in the borehole chambers with fittings of specified diameters and borehole pressure gauges. The working agent, produced water, is pumped through the tubing string. When pumping a working agent, the pressure is measured in the tubing string and in the annulus between the layers and opposite each layer. The dependence of the pressure in the annulus on the change in injection pressure in the tubing string is monitored, the flow from under the packer to the overpacker space is determined, and fluid flow between the packers opposite the formations is determined. Operation takes place without overflows. If pressure arises in the annulus by 1 MPa, regardless of the change in the injection pressure, the pressure is vented through the annular valve.

Example 2. Perform as example 1.

The three-packer assembly is installed in the injection well with a 5-inch production casing with an inner diameter of 130 mm. The production casing is patterned with a template with a length of 30 mm in diameter, 6 mm smaller than the diameter of the production casing.

With an unplanned landing of the packer to bring the packer into transport position, raise the tubing string by 2 m and slowly lower the string at a speed of no more than 0.1 m / s, passing the packer through the interval of unplanned landing.

The descent speed can withstand 0.09 m / s. They monitor the cable tension during descent, do not allow jerking and weakening the cable tension, when landing the tubing string on the wedge grip, do not allow the cable to enter the wedges, release the tubing string from the wedge grip, select the pipe lifting height when releasing the wedge grip 0.20 m.

Example 3. Perform as example 1.

The three-packer assembly is installed in the injection well with a 5-inch production casing with an inner diameter of 130 mm. The production casing is patterned with a template with a length of 100 mm and a diameter less than the diameter of the production casing by 4 mm.

With an unplanned landing of the packer to bring the packer into transport position, raise the tubing string by 3 m and slowly lower the string at a speed of not more than 0.1 m / s, leading the packer through the interval of unplanned landing.

The descent speed can withstand 0.08 m / s. They monitor the cable tension during descent, do not allow jerking and weakening the cable tension, when landing the tubing string on the wedge grip, do not allow the cable to enter the wedges, release the tubing string from the wedge grip, select the pipe lifting height when releasing the wedge grip 0.23 m.

During the descent, the layout is placed in the calculated interval without delays and premature setting of the packer.

Example 4. Perform, as example 1. Perform the installation of four-packer layout. An axial packer is used as the lower packer, persistent packers are used as the upper packers, configured to differently reduce the weight of the column: lower to smaller, medium to medium, upper to larger.

Example 5. Perform, as example 1. Perform the installation of two-packer layout. An axial packer is used as the lower packer, a persistent action packer is used as the upper packer.

The application of the proposed method will solve the problem of ensuring trouble-free descent and placement of a multi-packer arrangement in the well.

Claims (1)

A method of operating an injection well with a multi-packer arrangement, including launching the assembly into the well, packing packers and testing for their tightness, injecting the working agent simultaneously and separately into productive formations, characterized in that the production casing is patterned with a template from 30 to 100 m in length and diameter , smaller than the diameter of the production casing by 4-6 mm, in the process of patterning, note the intervals of planting and puffs of the template indicating the magnitude of these values, determine the causes of puffs and make decisions about the possibility of working out the wellbore and the possibility of further equipment placement, work out the production casing in the intervals for installing packers and in the intervals for planting and tightening the template, flush the well with backwash until a clean wash fluid comes out, mount the assembly with a plug at the end, packers, boreholes and devices, axial action packer is used as lower packer, persistent action packers are used as upper packers, cable is connected to devices, to the abel is fixed on the external surface of the assembly, the assembly is lowered into the well near the wellhead with measuring the length and patterning of the internal section of the assembly equipment, hydraulic tests of the run-down assembly are carried out for tightness, the plug is removed using cable technology, the assembly is lowered into the well to the required depth on the pump compressor pipes with measuring the length and patterning of the internal section of the tubing string, at the same time fasten the cable and the drain on the outer surface the cable is sheathed together with the tubing string, the descent speed can withstand no more than 0.1 m / s, the cable tension is monitored during descent, the cable is not jerked and the cable tension is weakened, and when the tubing string is planted on the wedge grip, it is not allowed the cable into the wedges, when the tubing string is released from the wedge grip, the pipe lifting height is chosen to be no more than 0.25 m, during the descent, the weight of the tubing string is not allowed to unload more than two tons, and if unplanned To bring the packer into the transport position, raise the tubing string by 2-3 m and slowly lower the string, leading the packer through the interval of unplanned landing, bind packers, adjust the layout to the specified interval with fitting pipes, spliced the cable with wellhead devices, mount the faceplate and the preventer, conduct a hydraulic test of the tubing string for leaks, calculate the lift of the tubing string with the comp new to packing packers, determine the required cable length from the wellhead to the controller panel, cut off excess cable, pass the cables through the cable entry, install the packers, recording changes in the weight of the tubing string, seal the cable glands and check the performance of the devices, compress packers, install pressure regulators in the borehole chambers with fittings of predetermined diameters or borehole manometers, and when operating a well when injecting a working agent they measure the pressure in the tubing string and in the annulus between the strata and opposite each reservoir, control the dependence of the pressure in the annulus on the change in injection pressure in the tubing string, the presence of overflow from the packer to the packer space is determined between the packers on the contrary, the fluid flow rate, and when pressure arises in the annulus, regardless of the change in the injection pressure, the pressure is vented through the annular valve.