Single well multiple oil layer plane branch multi-crack fracturing technology

Abstract

The invention discloses a single well multiple oil layer plane branch multi-crack fracturing technology. High-viscosity ahead fluid and low-viscosity ahead fluid with different viscosities are adopted, the single well multiple oil layer plane branch multi-crack fracturing technology is divided into two segments and injected into the stratum, the front semi-segment is injected with mixing fluid ofthe high-viscosity ahead fluid and a high-efficient fluid loss agent, a plurality of cracks with half-length greater than or equal to 300 m of artificial cracks are fractured in the stratum to be usedas main cracks, then the low-viscosity ahead fluid is injected into a rear semi-segment, and fraction shear of the low-viscosity ahead fluid of the rear semi-segment and the main crack wall surfacesis used for building a plurality of branch cracks on the main crack wall surfaces, so that a complex artificial crack area is formed on a whole reservoir stratum; and fracture of a plurality reservoirs at the same time is realized.

Description

technical field

[0001] The invention relates to a fracturing technology, in particular to a single-well multi-oil layer plane branch multi-fracture fracturing technology. It belongs to the technical field of oil and gas field production and development. Background technique

[0002] In the field of oil and gas field development technology, fracturing technology is an extremely important production and injection technology, especially in the development of low permeability oil and gas reservoirs, it plays a very important role in improving the production and recovery of oil and gas fields. However, the conventional vertical well or directional well fracturing technology only creates a simple artificial fracture on each oil and gas layer. The effective area of ​​the fracture and the effect of increasing production and injection are small, the effective stable period is short, and the production declines rapidly, which cannot meet the requirements. Long-term and efficient deve...

Examples

Embodiment 1

[0024] A single-well multi-reservoir planar branch multi-fracture fracturing process. The process uses high-viscosity pre-fluid and low-viscosity pre-fluid to inject into the formation in two stages. The mixed fluid of fluid loss agent is used to fracture a number of artificial fractures with a half-length greater than or equal to 300m in the formation as the main fractures, and then inject low-viscosity pre-fluid in the second half, and use the low-viscosity pre-fluid in the second half The friction and shear between the fluid and the wall of the main fracture creates multiple branch fractures on the wall of the main fracture, thereby forming a complex artificial fracture area on the entire reservoir; realizing simultaneous fracturing of multiple reservoirs.

Embodiment 2

[0026] A single-well multi-reservoir planar branch multi-fracture fracturing process, the specific implementation includes the following steps:

[0027] Step 1: Configure high-viscosity pre-fluid, high-efficiency fluid loss control agent and low-viscosity pre-fluid according to the ratio;

[0028] The high-viscosity preflux: is made of 1.5% dimethyl didocosyl ammonium chloride, 0.5% sodium 1-amino-4-naphthalenesulfonate, 1.0% potassium chloride and 97% water according to the above quality It is formed by mixing, wherein the chemical structural formula of dimethyl didocosyl ammonium chloride: [(CH 3 ) 2 N(C 22 h 45 ) 2 】 + Cl - ; The viscosity of the high-viscosity preflush at 25°C is 70-80mPa.

[0029] The high-efficiency fluid loss reducer: it is composed of 60% behenyl amidopropyl dimethyl glyceryl ammonium chloride, 15% rosin, and 25% sodium chloride according to the above mass ratio, with a particle size of 100-180 mesh .

[0030] The low-viscosity pre-fluid is pr...

Embodiment 3

[0035] Substantially the same as Example 2, the difference is: the high-viscosity pre-liquid: is made of 2.5% dimethyl docosyl ammonium chloride, 0.8% 1-amino-4-naphthalene sodium sulfonate, 3.0% Potassium Chloride and 93.7% water are mixed according to the above mass ratio, wherein the chemical structural formula of dimethyl didocosyl ammonium chloride: [(CH 3 ) 2 N(C 22 h 45 ) 2 】 + Cl - ; The viscosity of the high-viscosity preflush at 25°C is 70-80mPa.

[0036] The high-efficiency fluid loss reducer: it is composed of 75% behenyl amidopropyl dimethyl glyceryl ammonium chloride, 20% rosin, and 5% sodium chloride according to the above mass ratio, with a particle size of 100-180 mesh .

[0037] The low-viscosity pre-fluid is prepared by diluting the high-viscosity pre-fluid with clear water by 1 time; wherein, the viscosity of the low-viscosity pre-fluid at 25°C is 10-25mPa.

technical field

[0001] The invention relates to a fracturing technology, in particular to a single-well multi-oil layer plane branch multi-fracture fracturing technology. It belongs to the technical field of oil and gas field production and development. Background technique

[0002] In the field of oil and gas field development technology, fracturing technology is an extremely important production and injection technology, especially in the development of low permeability oil and gas reservoirs, it plays a very important role in improving the production and recovery of oil and gas fields. However, the conventional vertical well or directional well fracturing technology only creates a simple artificial fracture on each oil and gas layer. The effective area of ​​the fracture and the effect of increasing production and injection are small, the effective stable period is short, and the production declines rapidly, which cannot meet the requirements. Long-term and efficient deve...

Examples

Embodiment 1

[0024] A single-well multi-reservoir planar branch multi-fracture fracturing process. The process uses high-viscosity pre-fluid and low-viscosity pre-fluid to inject into the formation in two stages. The mixed fluid of fluid loss agent is used to fracture a number of artificial fractures with a half-length greater than or equal to 300m in the formation as the main fractures, and then inject low-viscosity pre-fluid in the second half, and use the low-viscosity pre-fluid in the second half The friction and shear between the fluid and the wall of the main fracture creates multiple branch fractures on the wall of the main fracture, thereby forming a complex artificial fracture area on the entire reservoir; realizing simultaneous fracturing of multiple reservoirs.

Embodiment 2

[0026] A single-well multi-reservoir planar branch multi-fracture fracturing process, the specific implementation includes the following steps:

[0027] Step 1: Configure high-viscosity pre-fluid, high-efficiency fluid loss control agent and low-viscosity pre-fluid according to the ratio;

[0028] The high-viscosity preflux: is made of 1.5% dimethyl didocosyl ammonium chloride, 0.5% sodium 1-amino-4-naphthalenesulfonate, 1.0% potassium chloride and 97% water according to the above quality It is formed by mixing, wherein the chemical structural formula of dimethyl didocosyl ammonium chloride: [(CH 3 ) 2 N(C 22 h 45 ) 2 】 + Cl - ; The viscosity of the high-viscosity preflush at 25°C is 70-80mPa.

[0029] The high-efficiency fluid loss reducer: it is composed of 60% behenyl amidopropyl dimethyl glyceryl ammonium chloride, 15% rosin, and 25% sodium chloride according to the above mass ratio, with a particle size of 100-180 mesh .

[0030] The low-viscosity pre-fluid is pr...

Embodiment 3

[0035] Substantially the same as Example 2, the difference is: the high-viscosity pre-liquid: is made of 2.5% dimethyl docosyl ammonium chloride, 0.8% 1-amino-4-naphthalene sodium sulfonate, 3.0% Potassium Chloride and 93.7% water are mixed according to the above mass ratio, wherein the chemical structural formula of dimethyl didocosyl ammonium chloride: [(CH 3 ) 2 N(C 22 h 45 ) 2 】 + Cl - ; The viscosity of the high-viscosity preflush at 25°C is 70-80mPa.

[0036] The high-efficiency fluid loss reducer: it is composed of 75% behenyl amidopropyl dimethyl glyceryl ammonium chloride, 20% rosin, and 5% sodium chloride according to the above mass ratio, with a particle size of 100-180 mesh .

[0037] The low-viscosity pre-fluid is prepared by diluting the high-viscosity pre-fluid with clear water by 1 time; wherein, the viscosity of the low-viscosity pre-fluid at 25°C is 10-25mPa.

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