Study and test on the new technology of multi-fracture fracturing

Due to the restriction of flooding patterns and fracturing technologies, it is not distinct to increase the output of super-low permeability reservoir in Changqing Oilfield only by increasing fracture length. Enlightened by the fact that the directional perforating can reduce the pressure of rock fracturing, the new technology of directional perforating and multi-fracture fracturing is firstly brought forward. This technology improves horizontal productive degree of oil layer and enlarges the drainage area through directionally perforating to induce oriented extension, forcing initial fracturing to change, and finally forming independent multi-fracturing. Through the study of entity model, it is recognized that perforating azimuth and horizontal stress difference are the key factors that affect the formation of multi fractures. Based on this recognition, fracturing technology is optimized. Two wells were tested on the spot in Huaqing area. It is approved initially that independent multi fractures is formed inside layers through the analysis on net pressure matching and microseismic frac mapping. At the initial production stage, the average daily oil production of trial wells increases by 0.91 tons (growing rate is about 26%) compared with the adjacent wells. This practice proves that production can be increased by increasing drainage area through multi-fracture fracturing.