Research Progress and Development Recommendations Covering Damage Mechanisms and Protection Technologies for Tight/Shale Oil and Gas Reservoirs

Tight and shale oil and gas reservoirs demonstrate unique geological characteristics such as extremely poor storage-flow quality, and multi-scale structure of storage and flow space. Those reservoirs are normally developed with staged fracturing of horizontal wells, which is made quite challenging by obviously different initial production rates and rapid declines. Further, uncertainty over the technical effects of drilling/completion and stimulation are significantly different. Currently, the major scientific issues that urgently need to be resolved include the requirement to reduce reservoir damage at all the exploration and development stages, to increase well production and stable production cycle, and to achieve economic and efficient development. Through the damage characteristics analysis of such reservoirs, and the main damage mechanisms summary during drilling/completion, stimulation and production, this paper introduces the basic principles and research progress of reservoir protection technologies such as the temporary plugging of physical particles and chemical filming, underbalanced drilling and completion, and interface modification, etc. The importance of damage prevention technologies in the timely discovery of tight/shale oil and gas reservoirs, correct evaluation and efficient development is elaborated with case studies. This paper also points out that integrated techniques in reservoir damage prediction and diagnosis system, multi-scale damage evaluation method, intelligent reservoir protection materials, liquid trap damage prevention measures, and reservoir protection-leakage control-permeability enhancement will be the important development trends in tight/shale oil and gas reservoir protection in the future.