Exploiting the vast quantities of in-place oil in some of China's large sedimentary basins will require understanding and identifying where new technologies and techniques can be applied to maximize production. Exploration in the Ordos basin in north-central China has demonstrated that tight oil reservoirs, such as the Chang 7 formation, are widely distributed; however, they remain relatively underdeveloped. These reservoirs are buried below the conventional oil layers, differ from them by geological composition, and their thin pay zones and low permeability present development challenges.

As part of a standard exploration and appraisal program, multiple vertical wells have been drilled to characterize the Chang 7 reservoir quality, and many were completed with only one hydraulic fracturing stage. Unfortunately, average hydrocarbon production was often low, and horizontal well completions with multiple transverse hydraulic fracturing treatments were required to obtain commercial flow rates. Part of the integrated workflow developed for the stimulation program requires the capture of reservoir, geological, and geomechanical properties for use in the design of the stages. The perforations were designed to allow for effective fracturing treatments across the lateral and were placed using the abrasive perforating technique. Additionally, one of these vertical wells was used for real-time microseismic fracturing monitoring to evaluate fracture geometry, fracture orientation, and azimuth.

Real-time technology and an integrated workflow effectively increased the understanding of where, when, and how to deploy hydraulic fracturing treatments in the lateral section of the study well. This optimization has resulted in more than an 8-fold increase in production compared to that from vertical wells. Considered a breakthrough, this project has resulted in the planning for additional horizontal wells.

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