RU2588081C1 - Well completion method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention can be used for intensification of well operation. In well tubing string is lowered to bottom and well is flushed with circulation, pumping through tubing string of pipes to bottom an aqueous solution of surfactant in amount of 3-4 m³ and flushing with water with density 1.17-1.19 g/cm³ in amount of 5-6 m³. Tubing string is lifted with makeup with well water with density of 1.17-1.19 g/cm³ up to wellhead. Well perforation is performed in intervals of productive stratum, tubing string with conical funnel and branch pipe is lowered at wellhead. Lower end of tubing string is installed 30-50 m above upper planned boundary of proppant bridge. Circulation is restored by pumping water with density 1.17-1.19 g/cm³. To create proppant bridge a proppant fraction of 16/20 and higher is used. Proppant is loaded into hopper by volume with simultaneous supply of water with density 1.17-1.19 g/cm³. Proppant concentration is maintained in water 50 kg/m³ at beginning and up to 100-150 kg/m³ at end of filling. After filling whole volume of proppant water supply is continued through funnel for displacement of proppant of tubing string in volume equal to volume of column. Process is withheld for proppant deposition during 4-8 hours, liquid circulation is restored, smooth tolerance of tubing string without circulation upper determine upper boundary of proppant bridge. If necessary proppant is added with low value of bridge or part of bridge is washed out with its large value, then string is lifted from well tubing.

EFFECT: shorter time for formation of proppant bridge and preventing flow of fracturing fluid through lower perforation holes.

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Description

The invention relates to the oil industry and can be used to intensify the operation of the well.

A known method of stimulating well operation, including filling the bottom, test injection of fracturing fluid and packs of fracturing fluid with proppant, adjusting the fracturing design and conducting the main fracturing process. To fill the face using proppant production of hydraulic fracturing, deliver the waste to the face in portions by means of an explosive grouting chalice with an expanded lower hole (RF patent No. 2541983, CL ЕВВ 43/26, publ. 02.20.2015).

Closest to the proposed invention in technical essence is a method of stimulating well operation, including bedding, test injection of fracturing fluid and packs of fracturing fluid with proppant, adjusting the fracturing design and conducting the basic fracturing process. To fill the face using proppant waste frack production. Deliver the waste to the slaughter in portions by means of a bailer (RF patent No. 2551586, class E21B 43/26, publ. 05/27/2015 - prototype).

A common disadvantage of the known methods is the length of the process of dumping the face, associated with the need for hoisting operations of the chipper.

The proposed invention solves the problem of accelerating the process of filling the face and eliminating the flow rate of the fracture fluid through the lower perforations during hydraulic fracturing.

The problem is solved in that in the method of completing a well, including perforating the well, filling the bottom with proppant and performing hydraulic fracturing, according to the invention, the tubing string is lowered into the well to the bottom and the well is circulated, the aqueous solution is pumped through the tubing string to the bottom surfactant in a volume of 3-4 m ³ and squeezed with water with a density of 1.17-1.19 g / cm ³ in a volume of 5-6 m ³ , raise the tubing string with topping the well with water with a density of 1.17-1 , 19 g / s m ³ to the mouth, perforate the well in the intervals of the reservoir, lower the tubing string with a cone-shaped funnel and pipe at the wellhead, the lower end of the tubing string is set 30-50 m above the planned upper boundary of the proppant bridge, pumping water with a density of 1.17-1.19 g / cm ³ restore circulation, to create a proppant bridge using proppant fractions 16/20 and higher, proppant is loaded into the funnel by volume with a simultaneous supply of water with a density of 1.17-1.19 gsm ³ , supporting The proppant concentration in water is 50 kg / m ³ at the beginning and up to 100-150 kg / m ³ at the end of the filling; after filling the entire proppant volume, water continues to flow through the funnel to displace the proppant from the tubing string in a volume equal to the column volume they carry out technological exposure to sediment proppant for 4-8 hours, restore fluid circulation, smooth tolerance of the tubing string without circulation determines the upper boundary of the proppant bridge, if necessary, fill up the proppant with a small value of mos either wash part of the bridge at its large size, and then lift the tubing string from the well.

SUMMARY OF THE INVENTION

When conducting hydraulic fracturing, it becomes necessary to isolate the underlying open intervals of the reservoir from the effects of fracturing. This is usually achieved by filling the underlying intervals of the well with sand or proppant production waste. However, the filling is very long and often does not achieve its goals, because the burst pressure penetrates through the bedding, and the burst fluid, although slowly, is filtered and consumed through the lower perforations. This disrupts the fracturing process. The proposed invention solves the problem of accelerating the process of filling the face and eliminating the flow rate of the fracture fluid through the lower perforations during hydraulic fracturing. The problem is solved as follows.

A string of tubing is lowered into the well to the bottom and the well is flushed with circulation by a kill fluid. An aqueous solution of a surfactant is pumped through the tubing string into the bottom in a volume of 3-4 m ³ and forced through with a density of 1.17-1.19 g / cm ³ in a volume of 5-6 m ³ . The surfactant solution occupies the near-wellbore zone and partially remains in the well. Raise the tubing string with topping the well with water with a density of 1.17-1.19 g / cm ³ to the mouth. Topping up the well allows you to maintain pressure on the bottom and eliminate the migration of fluids from the near-wellbore zone and back to the well. Perforation of the well is performed at intervals of the reservoir. A column of tubing is lowered with a cone-shaped funnel and a pipe at the wellhead. The lower end of the tubing string is set 30-50 m above the planned upper boundary of the proppant bridge. Injecting water with a density of 1.17-1.19 g / cm ³ restore circulation. To create a proppant bridge, proppant fractions of 16/20 and higher are used, i.e. fractions 12/18 or 10/14. Such fractions make it possible to create, according to the proposed technology, the most dense proppant pack, which almost completely eliminates leakage of fracturing fluid through the lower perforations. The proppant is loaded into the funnel by volume with a simultaneous supply of water with a density of 1.17-1.19 gsm ³ . As filling, the flow rate of the liquid with proppant increases, therefore, the proppant concentration in water is maintained at 50 kg / m ³ at the beginning and up to 100-150 kg / m ³ at the end of the filling. After filling the entire proppant volume, water continues to flow through the funnel to displace the proppant from the tubing string in a volume equal to the volume of the string. Spend technological exposure to precipitate proppant for 4-8 hours. As a rule, this time is sufficient for sedimentation and compaction of proppant at the bottom. Restore the circulation of fluid by injecting water with a density of 1.17-1.19 g / cm ³ . Stop circulation. By smooth tolerance of the tubing string without circulation, the upper boundary of the proppant bridge is determined. If necessary, add proppant when the bridge is small or wash part of the bridge when it is large. Raise the tubing string from the well. The equipment for hydraulic fracturing is lowered into the well, hydraulic fracturing is carried out and the well is mastered.

Case Studies

Example 1. Work is performed on completion of the well with the following characteristics: reservoir pressure 17 MPa, vertical depth 1631.12 m, extension 358.88 m, direction 426 mm, runoff depth 40 m, cement to the mouth, industrial conductor 323.9 mm, runoff depth 185 m, cement to the mouth, conductor 244.5 mm, runoff depth 351 m, cement to the mouth, production string 168 mm, runoff depth 1990 m, cement to the mouth.

A string of tubing is lowered into the well to the bottom and the well is washed with water circulation with a density of 1.17 g / cm ³ . A 1% aqueous solution of the ML-81B surfactant in a volume of 3 m ^{3 is} pumped through the tubing string into the bottomhole and forced through with a density of 1.17 g / cm ³ in a volume of 5 m ³ . Raise the tubing string with topping the well with water with a density of 1.17 g / cm ³ to the mouth.

Perforation of the well is carried out: in the interval 1951-1949 m - 10 holes, in the interval 1951-1949 m - 10 holes, in the interval 1949-1946 m - 15 holes, in the interval 1949-1946 m - 15 holes, in the interval 1942-1940 m - 20 holes, in the interval 1940-1937 m - 30 holes.

A column of tubing is lowered with a cone-shaped funnel and a pipe at the wellhead. The lower end of the tubing string is set 30 m above the planned upper boundary of the proppant bridge. The injection of water with a density of 1.17 g / cm ³ restore the circulation. To create a proppant bridge using proppant fractions 16/20. The proppant is loaded into the funnel by volume with a simultaneous supply of water with a density of 1.17 gsm ³ . The proppant concentration in water is maintained at 50 kg / m ³ at the beginning and up to 100 kg / m ³ at the end of the backfill. After filling the entire proppant volume, water continues to flow through the funnel to displace the proppant from the tubing string in a volume equal to the volume of the string. Spend technological exposure to precipitate proppant for 4 hours. Restore the circulation of the fluid by injecting water with a density of 1.17 g / cm ³ . Stop circulation. By smooth tolerance of the tubing string without circulation, the upper boundary of the proppant bridge is determined. The height of the bridge is normal. Raise the tubing string from the well. The equipment for hydraulic fracturing is lowered into the well, hydraulic fracturing is carried out and the well is mastered.

Example 2. Perform as example 1.

A string of tubing is lowered into the well to the bottom and the well is flushed with circulation by a kill fluid. A 2% aqueous solution of the ML-72 surfactant in the volume of 4 m ^{3 is} pumped through the column of tubing to the bottom and squeezed with water with a density of 1.19 g / cm ³ in a volume of 6 m ³ . Raise the tubing string with topping the well with water with a density of 1.19 g / cm ³ to the mouth. Perforation of the well is performed at intervals of the reservoir. A column of tubing is lowered with a cone-shaped funnel and a pipe at the wellhead. The lower end of the tubing string is set 50 m above the planned upper boundary of the proppant bridge. The injection of water with a density of 1.19 g / cm ³ restore the circulation. To create a proppant bridge using proppant fraction 12/18. The proppant is loaded into the funnel by volume with a simultaneous supply of water with a density of 1.19 gsm ³ . The proppant concentration in water is maintained at 50 kg / m ³ at the beginning and up to 150 kg / m ³ at the end of the backfill. After filling the entire proppant volume, water continues to flow through the funnel to displace the proppant from the tubing string in a volume equal to the volume of the string. Spend technological exposure to precipitate proppant for 8 hours. Restore the circulation of the fluid by injecting water with a density of 1.19 g / cm ³ . Stop circulation. By smooth tolerance of the tubing string without circulation, the upper boundary of the proppant bridge is determined. Add proppant in an amount of 10 kg. Raise the tubing string from the well. The equipment for hydraulic fracturing is lowered into the well, hydraulic fracturing is carried out and the well is mastered.

Example 3. Perform as example 1.

A string of tubing is lowered into the well to the bottom and the well is flushed with circulation by a kill fluid. A 3% aqueous solution of the surfactant OP-7 is pumped through the tubing string to the bottom in a volume of 3.5 m ³ and forced through with a density of 1.18 g / cm ³ in a volume of 5.5 m ³ . Raise the tubing string with topping the well with water with a density of 1.18 g / cm ³ to the mouth. Topping up the well allows you to maintain pressure on the bottom and eliminate the migration of fluids from the near-wellbore zone and back to the well. Perforation of the well is performed at intervals of the reservoir. A column of tubing is lowered with a cone-shaped funnel and a pipe at the wellhead. The lower end of the tubing string is set 40 m above the planned upper boundary of the proppant bridge. The injection of water with a density of 1.18 g / cm ³ restore the circulation. To create a proppant bridge using proppant fraction 10/14. The proppant is loaded into the funnel by volume with a simultaneous supply of water with a density of 1.18 gsm ³ . The proppant concentration in water is maintained at 50 kg / m ³ at the beginning and up to 130 kg / m ³ at the end of the backfill. After filling the entire proppant volume, water continues to flow through the funnel to displace the proppant from the tubing string in a volume equal to the volume of the string. Spend technological exposure to precipitate proppant for 6 hours. Restore the circulation of the fluid by injecting water with a density of 1.18 g / cm ³ . Stop circulation. By smooth tolerance of the tubing string without circulation, the upper boundary of the proppant bridge is determined. Wash 300 mm of the bridge. Raise the tubing string from the well. The equipment for hydraulic fracturing is lowered into the well, hydraulic fracturing is carried out and the well is mastered.

When conducting hydraulic fracturing in examples 1-3 was not observed the departure of the fracture fluid through the lower perforations. The creation time of the proppant bridge compared to the prototype was reduced by 6 hours.

The application of the proposed method will reduce the time of formation of the proppant bridge and eliminate the flow of rupture fluid through the lower perforations.

Claims (1)

A method of completing a well, including perforation of a well, proppant bottoming and hydraulic fracturing, characterized in that the tubing string is lowered into the well until the bottom and the well is circulated, the aqueous surfactant solution is pumped through the tubing string to the bottom in a volume of 3-4 m ³ and squeezed with water with a density of 1.17-1.19 g / cm ³ in a volume of 5-6 m ³ , raise the string of tubing with topping the well with water with a density of 1.17-1.19 g / cm ³ to the mouth, operate perf a well walkie-talkie in the intervals of the reservoir, a tubing string with a cone-shaped funnel and a pipe at the wellhead is lowered, the lower end of the tubing string is set 30-50 m above the planned upper boundary of the proppant bridge, with water injection with a density of 1.17-1 , 19 g / ^cm3 reduced circulation to create proppant bridge using 16/20 proppant fractions and higher proppant was charged into the funnel volume while supplying water density of 1,17-1,19 g / cm ^3, the concentration of proppant support in water of 50 kg / m ³ at the beginning and up to 100-150 kg / m ³ at the end of filling, after filling the entire volume of the proppant continue the supply of water through a funnel to displace proppant from the column of tubing in a volume equal to the volume of the column, is carried out technological the exposure time for proppant sedimentation for 4-8 hours, restore fluid circulation, smooth tolerance of the tubing string without circulation determine the upper boundary of the proppant bridge, if necessary, fill up the proppant with a small bridge size or wash part of the bridge when it is a large value, after which the column is raised from the well tubing.