Fracturing production-increasing method for 3.5-inch slim hole sidetracked well in ultra-low permeability oil reservoir

Abstract

The invention discloses a fracturing production-increasing method for a 3.5-inch slim hole sidetracked well in a ultra-low permeability oil reservoir. A strong-washing interval is quickly recognized though a logging response value of the ultra-low permeability oil reservoir, a production-increasing potential residual oil enrichment segment suitable for being transformed is divided by combining thereservoir interlayer stress characteristics, crakes are controlled by small-scale perforation fracturing to extend in the potential segment, the water breakthrough risk of an oil well is reduced by combining a water shutoff material, and finally, the fracturing production-increasing method for the 3.5-inch slim hole sidetracked well in the ultra-low permeability oil reservoir is formed. It can beensured the sidetracked well is precisely transformed in the longitudinal and transverse directions of the reservoir, reservoir residual oil is utilized maximally, by controlling the perforation thickness, controlling the construction scale and supporting key materials, the comprehensive water content is decreased, the single well output is increased, and the oil field production capacity is recovered.

Description

technical field [0001] The invention belongs to the technical field of oil production engineering reservoir transformation, and in particular relates to a 3.5-inch slim hole sidetracking fracturing stimulation method for ultra-low permeability oil reservoirs. Background technique [0002] The ultra-low permeability reservoirs such as Changqing Ansai and Jing'an C6 have entered the middle and late stage of development, with high recovery degree, and are in the medium-high water-cut production stage. Affected by the continuous opening and extension of water injection dynamic fractures, a water flooded zone has been formed along the main direction of the well pattern. Coupled with the influence of micro-fractures, the plane water flooding situation is complicated, and the distribution of remaining oil is uneven. The coring results of infill wells and inspection wells show that the remaining oil is relatively enriched outside the lateral range of 100m from the waterline in the r...

AI Technical Summary

Problems solved by technology

However, the existing methods of sidetracking reservoir stimulation for 3.5-inch slim holes have the following problems: First, most domestic oilfield sidetracking wells are located in medium-high permeability reservoirs, and are completed by direct perforation and put into production, which is not suitable for fracturing Improved ultra-low permeability reservoir

Second, multi-layer systems are developed in ultra-low permeability reservoirs, and vertically strong and weak water-washed layers are distributed alternately, making it difficult to identify water-flooded layers in sidetracking wells

Third, affected by the limitation of the size of the slim hole and the vertical heterogeneity of the reservoir, fractures tend to extend along the high-permeability section after general conventional fracturing, and high water cut and low production are likely to occur after fracturing