A 3.5-inch slim hole sidetracking fracturing stimulation method for ultra-low permeability reservoirs

Abstract

The invention discloses a 3.5-inch slim hole sidetracking fracturing production method for an ultra-low permeability oil reservoir. The well logging response value of the ultra-low permeability oil reservoir is used to quickly identify the strongly water-washed interval, and combined with the stress characteristics of the reservoir and interlayer to classify the suitable for reconstruction. In the remaining oil-enriched section with production potential, small-scale perforation fracturing is used to control the extension of fractures in the potential section, combined with water plugging materials to reduce the risk of water breakthrough in oil wells, and finally form a 3.5-inch slim hole sidetracking fracturing stimulation method for ultra-low permeability reservoirs . It can ensure that the sidetracking well can achieve precise stimulation in the vertical and horizontal directions of the reservoir, maximize the use of remaining oil in the reservoir, reduce the comprehensive water cut by controlling the perforation thickness, control the construction scale, and support key materials, increase the production of a single well, and restore the production capacity of the oilfield .

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