Concept, technology and practice of “man-made reservoirs” development

Oil and gas resources in low permeability and unconventional reservoirs are playing more and more important role in global energy supply, and are confronted with pressing problems in hard development, quick production decline, low recovery efficiency and high exploitation cost. Therefore, new development concept “man-made reservoirs” and a complete set of techniques and methods are proposed. With “sweet spots” as units, an integrated way of fracturing, injection and recovery is presented for the low permeability oil and gas resources to reconstruct the underground seepage field and petroleum output system and finally to realize enhancement of the recovery efficiency. Well-group development, fracturing and targeted fluid injection are applied to change the underground seepage field, supplement the formation energy, and form “man-made high permeability area” and “reconstructed seepage field”. By integration of information technology including big data, cloud computing, artificial intelligence etc., an integrated information management platform of “man-made reservoirs” including geology, development, production, management and decision has been set up, and large-scale, effective and sustainable development of this kind of resources are realized. Five series techniques are developed including 3D seismic geological evaluation for sweet spot area, well-group platform development, intellectual volume fracture, imbibition displacement and energy complement development, and intellectual management development based on cloud computing for “man-made reservoir”. In China, five blocks of shale gas and tight oil have been tested 235 times, and the effect of tight oil fracturing and output was 2 times better than that before, has achieved business development and showed bright perspectives.