Novel environment-friendly slickwater for shale gas

Abstract

The invention discloses a novel environment-friendly slickwater for shale gas. The slickwater comprises the following components in percentage by weight: 0.05%-0.15% of a resistance-reducing agent, 0.1%-0.3% of a discharge aiding agent, 0.2%-0.5% of a bactericide, 0.5%-1.5% of a clay stabilizer and the balance of clear water, wherein the resistance-reducing agent is a polyacrylamide emulsion; the discharge aiding agent is a mixture of cetyl trimethyl ammonium chloride and fatty alcohol; the bactericide is a mixture of sodium chloride and acrolein; and the clay stabilizer is potassium chloride. The slickwater is small harm to unconventional reservoir, clean, environment friendly and free of pollution and has higher proppant fracture conductivity so that longer effective fractures can be produced; and for unconventional oil and gas fields, the slickwater fracturing is an important measure to exploit the oil and gas fields and is also an effective way to reduce the oil production cost and increase mining-employed reserves.

Description

technical field [0001] The invention relates to the technical field of unconventional oil and gas field exploitation, in particular to a new type of environmentally friendly slippery water for shale gas. Background technique [0002] In the process of exploration and development of unconventional oil and gas reservoirs, due to the low porosity and low permeability characteristics of the reservoirs, most unconventional oil and gas reservoirs need to implement hydraulic fracturing to achieve industrial production value, but a large number of fracturing fluid damage proves that Conventional polymer fracturing fluid system damages the matrix permeability by more than 30%, which seriously affects the stimulation effect of fracturing; and also causes great damage to underground reservoirs. As the fracturing fluid leaks out, the cross-linking fluid is concentrated many times in the proppant-filled fractures. If the concentrated cross-linked polymer does not degrade after constructi...

AI Technical Summary

Problems solved by technology

[0002] In the process of exploration and development of unconventional oil and gas reservoirs, due to the low porosity and low permeability characteristics of the reservoirs, most unconventional oil and gas reservoirs need to implement hydraulic fracturing to achieve industrial production value, but a large number of fracturing fluid damage proves that Conventional polymer fracturing fluid system damages the permeability of the matrix by more than 30%, seriously affecting the stimulation effect of fracturing; and the damage to the underground reservoir is also great

As the fracturing fluid leaks out, the cross-linking fluid is concentrated many times in the proppant-filled fractures. If the concentrated cross-linked polymer is not degraded after construction or has a lot of residue after gel breaking, it will be of great help to propping the fracture. The diversion ability will cause serious damage, especially for unconventional reservoirs, which cannot achieve the expected stimulation effect; and pollute the environment