Method for production increasing and water controlling of sandstone gas reservoir of bottom water layer

Abstract

The invention relates to the technical field of oil and gas reservoir hydraulic fracturing transformation, in particular to a method suitable for production increasing and water controlling of a sandstone gas reservoir of a bottom water layer. The method comprises the following steps that A, characteristic parameters of a longitudinal ground stress section and a natural fracture are evaluated; and B, control factors of the fracture forming height and the supporting height are analyzed, specifically, 1 a reservoir stratum is pretreated through an acid fluid, and longitudinal over-extension of the initial fracture height is controlled; 2 an RPM fracturing fluid serves as a fracturing prepad fluid to be injected into a stratum for water proofing; 3-5 according to the variable parameter combination fracturing process technology, variable displacement construction is conducted through different viscosity of liquid carrying propping agents with different grain diameters and densities, fracture extending and reasonable and effective laying of the propping agents are controlled; 6 the propping agents in a wellbore are completely displaced to a fracture opening through low-viscosity liquid such as low-viscosity slick-water; and 7 if the bottom water layer is fractured in construction, after fracturing construction is completed and a fracture is closed, the weighted RPM fracturing fluid is injected into the fracture through a pressure limiting mode, so that water in the bottom water layer is prevented from going upwards.

Description

technical field

[0001] The invention relates to the technical field of hydraulic fracturing reconstruction of oil and gas reservoirs, and more particularly relates to a method suitable for fracturing and effectively controlling water in sandstone gas reservoirs with bottom water. Background technique

[0002] Due to the generally poor physical properties of tight sandstone gas reservoirs with bottom water, most gas wells must undergo fracturing to obtain industrial productivity. Fracturing technology has become one of the core technologies for production stimulation and effective development of such reservoirs. Since the tight sandstone bottom water gas reservoir is close to the bottom water layer, it is easy to communicate with the water layer during the fracturing process, resulting in a substantial increase in the water output after fracturing, and the serious water lock effect, which restricts the effective production of gas. At present, the fracturing stimulation of thi...