SU1740641A1 - Well completion method - Google Patents

Abstract

The invention relates to the oil and gas industry. The goal is to increase the efficiency of the method by reducing the time needed to complete the well while reducing the load on the cement ring. In the well 1, a string of pipes 2 is installed, and the tree branch valve 3 and the compressor 4 are attached to its wellhead. Gas is injected and through the annular space 5 forces the plugging fluid to the surface. Valves 6, 7, and 8 are then set to the open position, and valve 9 to the closed position. To divert the reservoir fluid, a flare outlet 10 with a choke device 11 is installed at the mouth. After lowering the fluid level to the shoe of the string of pipe 2, the valve 7 is closed and the gas is injected into the reservoir 12 until the well has been completely resorbed and the injected gas is mixed with reservoir. After reducing the pressure at the wellhead to the minimum and stabilization, the valve 6 is closed. At the end of the flare outlet, a choke device is installed and an inflow call is made. Pressure monitoring is carried out using valves 13 and pressure gauges 14 and 15 connected to the pipe string and annulus. 1 il. stjaa

Description

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The invention relates to the mining industry, in particular to the field of development of exploration and production wells that have come out of drilling or major repairs.

There is a known method of calling an inflow from a producing formation by creating airbags.

Closest to the invention is a method for inducing flow from a producing formation by lowering the level of fluid in the well with a compressor. The peculiarity of the process is the presence of a compressor, by means of which air is injected into the barrel through pump-compressor tubes, and the fluid filling the well is forced out to the surface through the annulus. After a certain amount of air is injected, the compressor is turned off, the pumped air from the tubing is released to the atmosphere and the well is stopped while waiting for the inflow from the reservoir.

The main disadvantages of this method are unproductive loss of working time for waiting for the inflow from the reservoir after reducing the level of plugging fluid in the wellbore, which can be measured for hours, and in some cases for days, as well as the possibility of destruction of the cement ring reservoir, composed of weakly cemented rocks, due to the creation of depression at the initial moment of development above the permissible value.

The purpose of the invention is to increase the efficiency of the method of well completion by reducing the time needed for completion while reducing the load on the cement ring.

SUMMARY OF THE INVENTION The essence of the invention is that in a well-known method of well development, which includes installing a pipe string in a well, displacing a well fluid into the annulus by injecting gas into the well pipe, blocking the annulus into the wellhead and causing inflow from the well to release excess pressure in the pipe string gas is produced before the well fluid is completely degassed in the pore space of the bottomhole zone and the injected gas is mixed with the reservoir gas; at the time of the well fluid level reduction to the pipe string shoe, and the moment of complete degassing of the well fluid is determined by reducing the pressure at the wellhead to the minimum during the gas injection process.

The drawing shows the scheme of development of the well by the proposed method.

The technological scheme contains a well 1 with pump-compressor pipes 2 installed in it, a tree armature 3, a compressor 4, an annular space 5, a gate valve 6-9, a flare branch 10, a choke device 11, a layer 12, valves 13, pressure gauges 14 and 15.

0 The method is carried out as follows.

After a major overhaul or drilling and perforation of the well 1, the installation of tubing 2 therein, the installation of a wellhead 3, connecting to the last compressor 4, air is pumped into the pumping compressor 2 and the displacement of the plugging fluid to the surface through

0 annulus 5. In this case, the valves 6, 7 and 8 are in the open position, and the valve 9 is in the closed position. By lowering the level of the well fluid to the tubing 2 shoe, valve 7

5 closes and begins the operation of injecting air into the formation 12 until the well fluid is fully degassed in the pore space of the bottomhole zone and the injected air is mixed with the formation gas.

At the initial moment of this operation, the destruction by the injected air of the mudcake formed on the walls of the borehole 1 as a result of filtration and absorption of the mud during drilling or overhaul occurs. Repression on formation 12 during this time period is maximum. In absolute value, it depends on the depth and design of well 1, reservoir properties 12, the duration and mode of drilling, the length of the overhaul, the parameters of the well fluid, the air injection rate, etc.

5 further, when the air, having destroyed the mudcake, starts pushing the well fluid into the depth of the reservoir 12, and the latter begins to be degassed by the reservoir gas, the repression all the time decreases even at the moment when the well fluid and the reservoir fluid are completely degassed gas, it will reach the minimum value.

Making sure that in the course of further injection of air into the formation 12, the pressure at the wellhead 1 stabilizes at the minimum mark, the compressor 4 stops and closes the valve 6. After installation at the end of the flare outlet 10 of the choke device 11, the valve 9

Claims (1)

the inflow of gas from reservoir 12 through tubing pipes 2 with a predetermined depression (due to the installation of the nozzle of the calculated diameter) is opened and produced. Upon receipt of a clean gas at the mouth of the valve, the valve 7 is opened and the development of well 1 continues both through the pump-compressor pipes 2 and the annular space 5 until the barrel is completely cleansed of liquid. The monitoring of changes in the parameters of air injection in the pump-compressor pipes 2 of the formation 12 and the development process of the well 1 as a whole is carried out with the help of pressure gauges 14 and 15. The invention method for developing the well, including installing a pipe string in the well, displacing the well fluid annular space injection into the column 0 five 0 gas pipes, overlapping the annular space at the wellhead and calling for inflow from the well by bleeding excess pressure in the pipe string, characterized in that, in order to increase the efficiency of the method by reducing the time required for completion of the well while reducing the load on the cement ring, gas is injected to full discharging the well fluid in the pore space of the wellbore zone and mixing the injected gas with the reservoir, while the annular space is blocked at the moment of decreasing the well level liquid up shoe tubing and the time of complete degassing of the wellbore fluid is determined to reduce the pressure at the wellhead to a minimum during the gas injection