RU2548271C1 - Oil producing well operation method - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: according to the method the hydraulic fracturing of formation is performed. After hydraulic fracturing of the formation in the well the proppant underflash is left. From above in addition from the coarse fraction proppant the bridge with a rated length is created. This length is selected in view of the condition of providing of counter-pressure on the proppant in the hydraulic fracturing crack sufficient for holding of proppant in a hydraulic fracturing crack at decrease of liquid level in the well down to the well bottomhole level. The package of downhole pumping equipment includes the antisand filter. During the well operation the antisand filter is placed directly over the proppant bridge. The liquid is sampled. The liquid level during liquid sampling - operation is maintained at the level of the deep-well pump.

EFFECT: increase in oil production.

1 ex

Description

The invention relates to the oil industry and may find application in the operation of an oil well.

There is a method of improving the hydrodynamic connection of a well with a producing formation, which includes sealing the annular space of a producing well, opening a producing formation, hydraulic fracturing of a producing formation by installing a packer above the roof of a perforated producing formation, injecting fracking fluid into a sub-packer zone, and create fracturing and squeezing pressures in a sub-packer zone into the resulting fracture fracturing fluid. When watering the production of a producing well to an extremely profitable value by geophysical surveys, the interval of water inflow into the reservoir is determined. After that, the blocking composition is injected into the interval of water inflow of the reservoir. Then make annular space sealing in the interval of perforation of the reservoir. Next, the productive formation is opened, with the exception of the intervals of insulated water inflow, by a perforating drill with a phasing angle of 60 ° with a diameter of inlet perforations in the casing of at least 12 mm and a perforation density of at least 18 holes / linear meter. In the intervals of perforation from top to bottom, an interval hydraulic fracturing of the producing formation is carried out with the formation of cracks and the hydraulic fracturing fluid is sold together with the crack fixer, in which proppant fractions from 30/60 mesh to 10/14 mesh are used in equal proportions, after which the production well is launched into operation (RF Patent No. 2485296, publ. 06/20/2013).

Closest to the proposed invention in technical essence is a method of hydraulic fracturing of a carbonate formation with bottom water. Provides increased efficiency of the method and its simplification. The inventive method includes the descent into the well of a string of tubing - tubing with a packer and its subsequent landing, the descent into the tubing string of a string of flexible pipes - GT below the lower end of the tubing, pumping a water-insulating cement through a flexible pipe, fracturing a carbonate formation with bottom water . The lower end of the GT is lowered to the level of the oil-water contact - the OWC, the space between the tubing and the GT columns is sealed, the injection of water-insulating cement along the GT makes the bottom water in the carbonate formation isolated from the bottom to the level of the OWC. After that, the space between the tubing string and HT columns is depressurized and the GT column is lifted so that its lower end is 1-2 meters below the roof of the carbonate formation, after which the total volume of the fracturing fluid is determined by the analytical expression. Seal the space between the tubing and GT columns and pump the first portion of the fracture fluid into the GT in the amount of 60-70% of the total volume of the fracture fluid under pressure of not more than 25 MPa and at a speed of not more than 2 m ³ / min. After that, the remaining volume of the fracture fluid is pumped into the GT in 3-5 cycles, alternating with the proppant injection. As this agent, 25% hydrochloric inhibited acid is used. The volume of acid is determined depending on the thickness of the productive part of the carbonate formation based on the volume of 0.2 m ^{3 of} acid per 1 m of thickness of the formation for each injection cycle. At the end of the last injection cycle, acid is pumped with an aqueous solution of a surfactant in the volume of the GT column, followed by an exposure of 1-2 hours. Then the GT column is removed from the tubing string and the well is put into operation (RF Patent No. 2460875, publ. 09/10/2012 - prototype).

A disadvantage of the known methods is that the proppant is removed from the crack fixed during proppant fracturing with a significant decrease in bottomhole pressure and the fracture is closed, as a result, during production with significant depression, even while maintaining reservoir pressure, the productivity of the well decreases, the duration of the fracture effect is reduced layer. Limiting the magnitude of depression does not prevent proppant removal, well production is reduced, and potential oil recovery is not achieved.

The proposed invention solves the problem of increasing oil production.

The problem is solved in that in the method for operating an oil producing well, including hydraulic fracturing and subsequent fluid withdrawal, according to the invention, after the hydraulic fracturing of the formation, underproduction proppant is left in the well, and a bridge from a large fraction of proppant is additionally created on top to form the layout of the downhole pumping equipment include a sand filter, during well operation, the shoe is placed directly above the proppant bridge, and the fluid level during operation hold at the level of the deep pump.

SUMMARY OF THE INVENTION

One of the most effective ways to intensify the selection from the well is hydraulic fracturing with subsequent consolidation of the resulting proppant fractures.

However, a significant decrease in bottomhole pressure for maximum production during operation may result in loss of well productivity and a decrease in potential production. The proposed invention solves the problem of increasing oil production. The problem is solved as follows.

When operating an oil well, with a decrease in oil production, hydraulic fracturing is performed. After hydraulic fracturing, a proppant of undersupply is left in the well, and a bridge from a large proppant of a large fraction predominantly 5-10 m high is additionally created on top. The proppant is selected to create a bridge of the same fraction, or larger than the proppant of the underproduct, but not less than 12/18 mesh. The length of the proppant bridge, therefore, the proppant volume to create the bridge is selected based on the conditions for providing back pressure on the proppant in the hydraulic fracture, sufficient to hold the proppant in the fracture while creating a decrease in the liquid level in the well to the bottom hole level.

The hydraulic fracturing assembly is removed from the well without washing the bottom from the proppant. For the operation of the well, the layout of the downhole pumping equipment is being introduced, which additionally includes a sand filter. The layout shoe is located 1-3 m above the sand bridge to ensure maximum depression. Operation is carried out at a liquid level at the pump intake, ensuring maximum depression on the formation.

Since a large fraction proppant bridge combined with an undersupply proppant volume creates back pressure on the proppant in the fracture fracture and prevents proppant from escaping even with large depressions on the formation, this solution allows to minimize the depth of the depth pump and create the maximum depression on the formation with establishing the fluid level at the bottom of the pump. Due to this, it is possible to increase the flow rate of the well and extend the effect of increasing the flow rate from hydraulic fracturing. A large proppant fraction helps to reduce hydraulic resistance to fluid flow, contributes to the greatest degree of compaction of proppant undersupply and is not amenable to ablation even with intensive fluid withdrawal from the reservoir.

This solution ensures well operation with maximum depression without the risk of proppant removal and productivity loss in this regard.

Case Study

An oil well that explodes a carbonate reservoir at depths of 1067-1079 m is used in an oil reservoir with a long service life and degassed oil. The initial production rate of the well was 6 m ³ / day. Over the three years of well operation, the flow rate decreased to 3 m ³ / day. To increase the flow rate in the well, hydraulic fracturing is performed. Three fractions of proppant are pumped into the fracture gap: 20/40 mesh - 15%, 16/20 mesh - 70%, 12/18 mesh - 15%. The proppant fraction 16/20 mesh is the main in relation to the entire proppant volume, larger (12/18 mesh and larger) and accordingly more conductive, at the final stage it takes up a smaller volume, as a result, a crack is created with a wing length of 100 m with a high conductivity in the near-wellbore part. The proppant undersupply volume is 0.3 m ³ , while the proppant concentration in the carrier fluid of the undersupply volume is maximum.

After completion of the hydraulic fracturing process and pressure reduction in the well, 0.6 m ^{3 of} proppant fraction 18/12 are loaded into the well along the string of tubing used during hydraulic fracturing and technological exposure is carried out for 5 hours to sediment the proppant. As a result, a bridge of proppant 5 m high is created over the perforation interval. A tubing string is lifted from the well; used during hydraulic fracturing. A tubing string with a sucker rod pump and a sand filter at the end is lowered into the well. A sand filter is placed directly above the proppant bridge at a distance of 2 m. The well is put into operation and the liquid level in the well is set at the depth of the pump. As a result, the flow rate of the well increased to 12 m ³ / day. As a result of well operation during the year, a marked decrease in production rate due to a decrease in productivity was not noted.

Application of the proposed method will increase the production rate of an oil well.

Claims (1)

A method of operating an oil producing well, including hydraulic fracturing and subsequent fluid withdrawal, characterized in that after the hydraulic fracturing, the proppant is left underpowered, and an additional bridge is created from the proppant of a large fraction with a length selected based on the condition of providing back pressure on the proppant in the hydraulic fracture sufficient to hold proppant in the hydraulic fracture while lowering the liquid level in the well to the bottom hole level, ki downhole pumping equipment include screened pipe, during operation of the well-Control filter is placed directly over the bridge of the proppant, and during operation the liquid level is maintained at a downhole pump.