Method for creating branch seam with temporary plugging and pressure buildup using super absorbent resin

Abstract

A method for creating a branch fracture with temporary plugging and pressure buildup using super absorbent resin, comprising: setting a fracturing packer to fracture a target layer by pad fluid to form a main fracture; injecting into the main fracture pad fluid mixed with salt-intolerant super absorbent resin and performing replacement till depth of the main fracture, and then injecting pad fluid mixed with strong salt-tolerant super absorbent resin; after the strong salt-tolerant super absorbent resin absorbs water and expands to form a temporary plugging layer, re-injecting the pad fluid to create a branch fracture with pressure buildup; and lifting injection pressure to break up the temporary plugging layer formed by the strong salt-tolerant super absorbent resin to form residue, transporting the residue to the depth of the main fracture to bridge the temporary plugging layer formed, and re-building up pressure to create a branch fracture.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of priority from Chinese Patent Application No. 201811495751.X, filed on Dec. 7, 2018. The content of the aforementioned application, including any intervening amendments thereto, is incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]The invention relates to the field of petroleum engineering hydraulic fracturing, and in particular, to a method for creating a branch fracture with temporary plugging and pressure buildup using super absorbent resin.BACKGROUND OF THE INVENTION[0003]With the acceleration of the exploration and development of unconventional oil and gas resources such as tight oil, shale gas and coalbed gas, the effective development of unconventional oil and gas resources has become a hot issue in the world. Hydraulic fracturing technology is an effective means for economic development of unconventional oil and gas. However, in order to form a sand packed fracture with hig...

AI Technical Summary

Benefits of technology

[0022]In the present invention, temporary plugging may be performed at the front end and at the depth of the main fracture, resulting in a larger fracture network area and stronger connection between reservoirs, which provides more channels for oil and gas transportation and greatly increases the production of oil and gas wells.

[0023]Second, the super absorbent resin absorbs water and does not absorb oil, and does not react with the reservoir during the whole construction process, without damaging the reservoir, and also does not need to be prepared during the entire construction process. The super absorbent resin can be used as needed. The construction process is simple. After the completion of the construction, the super absorbent resin is dissolved by a mixed solution of ammonium persulfate and hydrochloric acid, and almost no resin residue exists after flow back, with little damage to fracture conductivity.

Problems solved by technology

With the acceleration of the exploration and development of unconventional oil and gas resources such as tight oil, shale gas and coalbed gas, the effective development of unconventional oil and gas resources has become a hot issue in the world.

At present, the main disadvantage of conventional hydraulic fracturing technology is that it is often difficult to extrude a complex multi-level fracture network in reservoirs with abundant oil and gas and most fracture networks formed have a single shape and few horizontal and vertical expansions.

Even some fracturing construction can only extrude one main fracture in the reservoir, which has almost no effect on the transformation of the reservoir, resulting in very low fracturing efficiency.

This makes it difficult to transport and produce oil and gas, and the yield is not significantly improved after fracturing construction.

How to extrude a branch fracture to form a multi-level fracture network system has become a bottleneck problem restricting the development of hydraulic fracturing technology.

Images