RU2588108C1 - Horizontal well completion method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention can be used for intensification of oil production from producing carbonate formations penetrated by wells with open horizontal shafts. Horizontal well completion method consists in lowering production string with starting clutches and with a funnel at end, arrangement of a funnel in range of shoe of production string, lowering flexible flush-joint pipe with jet nozzle at end inside tubing string, input of jet nozzle in horizontal well uncased and arrangement at bottom hole, at open tube valve at wellhead pumping of acid solution with creation of flow rate providing effect of "cutting" rock at open casing valve at flush-joint pipe filling borehole water solution of surfactant, closing of casing valve and forcing-through solution of surface active substance at flush-joint pipe to formation, closing valve on tube space of flexible flush-joint pipe, at closed annular and tube space through annular space acid solution is flushed in well bore, in formation with stepped pressure rise and exposure at each stage, process withhold for purpose of acid reaction with rock, washing well shaft, lifting of flexible flush-joint pipe of well, pumping of inert gas through annular space with extraction of liquid via tubing string, pumping of liquid into well killing, development of well. Wherein in horizontal bore is placed an assembly with bit, equal to diameter of horizontal shaft with drive, horizontal borehole is washed with rotation and reciprocation arrangement of direct flushing with 0.1-0.3 % solution of surfactant in formation water in volume not less than 25 m³ to clean water, assembly is lifted in vertical borehole and held for 30 minutes, then horizontal borehole is gauged by assembly to face. Pumping of acid through flexible flush-joint pipe is carried out at pressure not less than 20 MPa and flow rate of not less than 3 l/s.

EFFECT: high efficiency of acid treatment of well due to creation of hydrodynamic communication with interlayers not exposed to acid effect.

1 cl, 1 ex

Description

The invention relates to the oil industry and may find application in the intensification of oil production from a productive carbonate formation, opened by a well with an open horizontal wellbore.

There is a known method of well completion in which an acid solution is injected into a horizontal open wellbore in a hydromonitoring mode, the hydromonitoring effect is carried out by means of a nozzle placed at the end of a flexible sleeveless pipe. The nozzle is placed on the bottom of the wellbore. The acid solution is pumped by circulation with the wellhead; simultaneously with the circulation of the acid solution, a flexible sleeveless pipe is lifted from the well with a speed not exceeding the rate of filling the wellbore with an acid solution. After filling the horizontal well with an acid solution, the acid solution is pushed into the formation with a stepwise increase in pressure and exposure at each stage. The flexible sleeveless pipe with the nozzle for the bottom of the well is lowered again and the operations of filling the wellbore with an acid solution and forcing are repeated. Carry out technological exposure for the reaction of the acid solution with the rock. A flexible sleeveless pipe is raised to the inert gas pumping interval, the inert gas is pumped, and the level recovery curve is taken. The wells are cycled killing in the “water injection - holding - oil bleeding” mode until the oil is completely bled, the downhole pump is lowered and the well is put into operation (RF patent No. 2490442, published on 08/20/2013).

The disadvantage of this method is that during acid treatment, the acid reacts with the rock unevenly along the length of the horizontal trunk.

Closest to the proposed invention in technical essence is a method of completing a well, comprising pumping an acid solution by circulation with the wellhead by means of a nozzle placed at the end of a flexible sleeveless pipe, while circulating the acid solution, lifting a flexible sleeveless pipe from a well at a speed not exceeding the filling rate the wellbore with an acid solution, after filling the horizontal wellbore with an acid solution, pushing the acid solution into the formation with a stepwise by raising the pressure and holding at each stage, carrying out technological exposure for the reaction of the acid solution with the rock, pumping inert gas, fixing the level recovery curve, killing the well and developing the well, according to the invention, the tubing string is lowered into the well of the shoe of the production string first with start-up couplings and a funnel at the end, a flexible sleeveless coupling pipe with a hydraulic nozzle is lowered inside the tubing string before selling acid in the formation, the horizontal wellbore with an open annular space is filled through a flexible sleeveless pipe with an aqueous solution of a surfactant, with a closed annular space, an aqueous solution of a surfactant is forced into the formation, technological exposure is carried out until oil floats into the well, then the annulus is produced squeezing the acid solution, carry out technological exposure for the reaction of the acid solution with the rock, wash the wellbore, lift from the wells They have a flexible sleeveless pipe with a hydraulic nozzle, and inert gas is pumped through the annulus with fluid withdrawal along the tubing string, after the well is developed, geophysical studies of the horizontal wellbore on the flexible pipe are carried out using thermometry and debitometry methods, after obtaining the results of the study, “idle” are detected intervals and, comparing the geophysical material with final logs, determine the "idle" horizontal well intervals having high e filtration-capacitive properties, by installing a flexible sleeveless pipe, install a hydraulic monitor nozzle in these horizontal hole intervals, press the end of the hydraulic nozzle against the horizontal barrel wall and circulate the acid solution through a flexible sleeveless pipe, hydraulic monitor nozzle and tubing string until a well is formed in the rock (channel) and an increase in the surface area of the exposure interval, then an acid solution is forced through the annulus, ny exposure process for the reaction of acid with the rock, raised from the well clutchless flexible tube with a jetting nozzle, and pumping the inert gas is conducted from the annulus fluid by a column selection tubing (RF patent №2541986, publ. 02/20/2015 - prototype).

When implementing the known method, the uniformity of the acid effect is ensured along the length of the horizontal wellbore, however, there is no hydrodynamic connection with the interlayers not covered by the acid effect.

The proposed invention solves the problem of increasing the efficiency of acid treatment of the well by creating a hydrodynamic connection with interlayers not covered by acid exposure.

The problem is solved in that in a method for completing a horizontal well, including lowering a tubing string with start-up couplings and with a funnel at the end, placing a funnel in the interval of the shoe of the production string, lowering a flexible sleeveless coupling pipe with a hydraulic nozzle at the end inside the tubing string , introducing a hydraulic nozzle into a horizontal open-hole wellbore and placing it at the bottom of the well, with an open annular valve at the wellhead pumping an acid solution with the creation of flow rate, providing the effect of "cutting" the rock, with an open annular valve through a sleeveless pipe, filling the horizontal wellbore with an aqueous solution of a surfactant, closing the annular valve and forcing a solution of surfactant through a sleeveless pipe into the formation, closing the valve on the pipe space with a flexible couplingless pipes, with a closed annulus and tube space through the annulus pushing the solution of acid in the wellbore into the formation with a stepped increasing pressure and holding at each stage, carrying out technological exposure for the reaction of the acid solution with the rock, flushing the wellbore, lifting the flexible sleeveless pipe from the well, pumping inert gas through the annulus with fluid sampling along the tubing string, pumping the kill fluid into the well , development of a well, according to the invention, preliminarily, in a horizontal well, an arrangement with a bit equal to the diameter of the horizontal well is placed, with a drive, the horizontal well is washed wells with rotation and pacing of the layout by direct washing with a 0.1-0.3% solution of a surfactant in produced water in a volume of at least 25 m ³ to clean water, lift the assembly into a vertical wellbore and hold for 30 minutes, after that, the horizontal wellbore is patterned by the layout before the bottom, and when pumping the acid solution through a flexible sleeveless pipe, the acid is pumped at a pressure of at least 20 MPa and a flow rate of at least 3 l / s.

SUMMARY OF THE INVENTION

In connection with the active development of the drilling of horizontal wells of various designs and their lengths to increase their efficiency, today there is a need to improve the technology of acid treatment of horizontal wells. One of the reasons for the low efficiency of the production of treatments in horizontal boreholes using traditional technology is that during the processing the hydrodynamic connection with interlayers not covered by acid exposure is not achieved.

The proposed invention solves the problem of increasing the efficiency of acid treatment of the well by creating a hydrodynamic connection with the interlayers not covered by acid exposure. The problem is solved as follows.

In a horizontal wellbore, an arrangement with a bit equal to the diameter of the horizontal wellbore is placed with a drive. A 0.1-0.3% solution of a surfactant in formation water is pumped through the assembly in a volume of at least 25 m ³ to clean water, thereby washing the horizontal wellbore. At the same time, the wash solution causes the bit to rotate. In this case, the arrangement with the bit is moved along the horizontal wellbore with rotation, i.e. pacing layouts with direct flushing. Due to this, the diameter of the horizontal trunk is slightly increased. But the main effect of pacing occurs due to penetration into the near-wellbore zone due to the impact of shock loads from the bit of the washing solution. Wash solution, being "native" to the reservoir fluid, because It is based on the formation water of this reservoir and creates permeability in the pores of the near-wellbore reservoir collector equal to the initial, prior to drilling and disrupted by the clogging effect of the drilling fluid and bit during drilling. Raise the layout in a vertical wellbore and incubated for 30 minutes. At the same time, in the horizontal wellbore, all flows of the wash solution and formation fluid from the formation cease. A horizontal wellbore is patterned with the layout before the bottom, i.e. to the far end of the horizontal wellbore, with flushing to remove any rock particles remaining in the wellbore. Raise the layout from the well.

A string of tubing with start-up couplings and a funnel at the end is lowered into the well. The funnel is placed in the interval of the shoe casing. A flexible sleeveless pipe with a hydraulic nozzle at the end is lowered inside the tubing string. The hydraulic monitor nozzle is brought into a horizontal uncased wellbore and placed on the bottom of the well. With an open annular valve at the wellhead, an acid solution is pumped to create a flow rate that provides the effect of "cutting" the rock. The volume of the acid solution is chosen equal to the volume of the annulus of the well. When pumping an acid solution through a flexible sleeveless pipe, acid is pumped at a pressure of at least 20 MPa and a flow rate of at least 3 l / s. As studies have shown, such a regime provides the maximum effect from hydromonitor exposure. Simultaneously with the supply of the acid solution, a flexible sleeveless pipe is moved along the horizontal wellbore. If necessary, the acid-hydromonitor impact on the formation is repeated in a similar manner up to 3 times.

The annulus is the space between the flexible sleeveless pipe and the tubing string. The annulus is the space between the tubing string and the production well string. The pipe space is the space of a flexible sleeveless pipe in the well.

The hydraulic monitor nozzle is again placed on the bottom of the well, with an open annular valve through a sleeveless pipe, the horizontal wellbore is filled with an aqueous solution of a surfactant. The annular valve is closed and the surfactant solution is forced through the sleeveless pipe into the formation.

An aqueous solution of a concentration sufficient to wash the oil from the rock is used as a surfactant solution. As a rule, this concentration is 0.1% or more. As a surfactant, any one capable of washing off oil is used, for example, ML-81B, ML-72, OP-7, etc.

Close the valve on the pipe space, i.e. on a flexible sleeveless pipe. With a closed annulus and tube space through the annulus, the acid solution in the wellbore is forced into the formation. The acid solution is pushed into the formation with a stepwise increase in pressure and exposure at each stage. When pushing an acid solution located in the wellbore into the formation, the pushing is performed with a stepwise increase in pressure and technological exposure at each stage. The pressure rise is carried out with increasing pressure from a stage to a stage from 3 to 6 MPa, technological exposure at each stage is carried out until the pressure drops to 2 MPa.

Spend technological exposure for the reaction of the acid solution with the rock mainly within 2-4 hours. The wellbore is flushed, a flexible sleeveless pipe is lifted from the well.

Inert gas is pumped through the annulus with fluid withdrawal along the tubing string. Killing fluid is pumped into the well. After well development, geophysical studies of a horizontal wellbore on a flexible pipe are carried out using methods of thermometry and debitometry.

As a result, it is possible to increase the flow rate of the well by creating a hydrodynamic connection with interlayers not covered by acid exposure.

Concrete example

Work is being carried out on an oil well with a horizontal wellbore 200 in length at a depth of 1,432 m. The diameter of the horizontal wellbore is 144 mm. The well is filled with a kill fluid. The 114 mm shoe of the production casing is located at a depth of 1232 m. A water-saturated formation is located 5 m below the bottom of the productive formation.

The F32SP-95 bit is lowered into the well on the drill pipe string, and the mechanical rotor is installed. Carry out the layout with direct washing, pumping through the layout of a solution of the surfactant ML-81B in produced water in a volume of 25 m ³ to clean water. When pumping, the concentration of surfactant in the solution is maintained in the range of 0.1-0.3%. Raise the layout in a vertical wellbore and incubated for 30 minutes. After that, the horizontal wellbore is patterned by the layout before the bottom with washing with the surfactant solution used above.

A string of tubing with start-up couplings and a funnel at the end is lowered into the well. The funnel is placed in the interval of the shoe casing. A flexible sleeveless pipe with a hydraulic nozzle is lowered inside the tubing string.

A flexible, sleeveless pipe 38 mm in diameter with a jet nozzle at the end is lowered into a horizontal open-cased wellbore. The nozzle is placed on the bottom of the wellbore. With an open annular valve at the wellhead, a 15% hydrochloric acid solution is circulated with the wellhead. When pumping an acid solution through a flexible sleeveless pipe, acid is pumped at a pressure of 22 MPa and a flow rate of 4 l / s.

The volume of the acid solution is chosen equal to the volume of the annulus of the well, i.e. equal to 4.4 m ³ . Simultaneously with the supply of the acid solution, a flexible sleeveless pipe is moved along the horizontal shaft. With the annular valve open, the horizontal wellbore is filled through a flexible sleeveless pipe with an aqueous solution of a surfactant — 0.1% aqueous solution of ML-81B. With a closed annular valve through a flexible sleeveless pipe, an aqueous solution of a surfactant is forced into the formation. Acid annulus is injected with an acid solution into the formation with a stepwise increase in pressure and holding at each stage in the following mode: 3 MPa - 15 minutes until the pressure drops to 2 MPa, 3 MPa - 15 minutes until the pressure drops to 2 MPa, 4 MPa - 20 minutes to reduce the pressure to 2 MPa, 5 MPa - 25 minutes to reduce the pressure to 2 MPa, 6 MPa - 30 minutes to reduce the pressure to 2 MPa. Spend technological exposure 3 hours for the reaction of the acid solution with the rock.

Washed well. Inert gas is pumped through the annulus with fluid withdrawal along the tubing string. Killing fluid is pumped into the well. After well development, geophysical studies of a horizontal wellbore on a flexible pipe are carried out using methods of thermometry and debitometry.

As a result, the flow rate of the well was 20 m ³ / day at 10% water cut of the produced products - oil. Oil production is maintained for 2 years of well operation. A decrease in the production rate of the prototype is observed during the first 6 months of well operation.

The application of the proposed method will allow to solve the problem of increasing the efficiency of acid treatment of the well by creating a hydrodynamic connection with interlayers not covered by acid exposure.

Claims (1)

A method for completing a horizontal well, including lowering a tubing string with start-up couplings and with a funnel at the end, placing a funnel in the interval of the shoe of the production string, lowering a flexible sleeveless coupling pipe with a hydraulic nozzle at the end inside the tubing string, introducing a hydraulic nozzle into the horizontal open hole and placement at the bottom of the well, with an open annular valve at the wellhead pumping the acid solution with the creation of a flow rate that ensures e the effect of “cutting” the rock, with an open annular valve through a sleeveless pipe, filling the horizontal wellbore with an aqueous solution of a surfactant, closing the annular valve and forcing a solution of surfactant through the sleeveless pipe into the formation, closing the valve on the pipe space of a flexible couplingless pipe, closed annular and tubular space through the annular space, pushing the acid solution in the wellbore into the formation with a stepwise pressure increase and holding at each stage, carrying out technological exposure for the reaction of the acid solution with the rock, flushing the wellbore, lifting a flexible sleeveless pipe from the well, pumping inert gas through the annulus with fluid sampling along the tubing string, injecting the kill fluid into the well, developing the well characterized in that the arrangement with a bit equal to the diameter of the horizontal shaft with a drive is preliminarily placed in a horizontal wellbore, and the horizontal wellbore is washed with rotation and flow by pressing the assembly by direct washing with a 0.1-0.3% solution of a surfactant in produced water in a volume of at least 25 m ³ to clean water, raise the assembly into a vertical wellbore and hold for 30 minutes, then horizontal the wellbore is assembled before the bottom, and when pumping an acid solution through a flexible sleeveless pipe, acid is pumped at a pressure of at least 20 MPa and a flow rate of at least 3 l / s.