长庆气区低渗透气藏开发技术新进展及攻关方向

鄂尔多斯盆地发育上、下古生界两套含气层系，天然气资源量丰富，但储层非均质性强，开发难度大。近10年来，中国石油长庆油田公司相继实现了低渗透碳酸盐岩气藏（靖边气田）、低渗透砂岩气藏（榆林气田）和致密砂岩气藏（苏里格气田）的经济有效开发。近期该公司以建设“西部大庆”为目标，低渗透气藏开发水平显著提高，又取得了一系列的新进展：①水平井已经成为低渗透致密气藏开发的主体技术，其单井产气量超过直井的3倍，产能建设比例保持在50%以上；②丛式井钻完井技术、工厂化作业模式等提高了单井产量，降低了开发成本；③井、集气站、处理厂数字化建设提升了气田的生产管理水平。截至2012年底，长庆气区建成了年产300×10⁸ m³以上的天然气生产能力，当年产气量达到290×10⁸ m³，长庆气区已经成为我国重要的天然气生产基地。下一步该公司将按照“攀峰工程”发展规划，以提高单井产量、提高采收率、降低开发成本为目标，加强4个方面的技术攻关：水平井加体积压裂技术系列、储气库建设技术系列、多层系气藏立体开发技术系列和低产低效井综合治理技术系列。

Latest progress in development technologies for low-permeability gas reservoirs in the Changqing Gas Zone

The Upper and Lower Paleozoic gas rich reservoirs were discovered in the Ordos Basin, but due to their great heterogeneity, they are extremely difficult to develop. Over the last decade, commercial production has been achieved by the PetroChina Changqing Oilfield Company successively in the low permeability carbonate gas reservoirs in the Jingbian Gas Field, the low permeability sand gas reservoirs in the Yulin Gas Field, and the tight gas reservoirs in the Sulige Gas Field. In recent years, with the goal of building another Daqing in West China, this company has made great achievements in the development of low permeability gas reservoirs. First, the single well production of horizontal wells is twice more than that of vertical wells; above 50% of the cumulative productivity is attributed to horizontal wells, which has become the main type of wells for the development of low permeability gas reservoirs. Second, the factory like drilling and well completion practices help enhance the single well production and reduce the development cost. Third, the digitalized construction of wells, gas gathering stations, gas processing plants, etc. help improve a gas field’s production and management level. By the end of 2012, a gas field has been put into production with an annual capacity of 30 BCM in the Changqing Gas Zone, which has become one of the most important bases of gas production in China. In order to further enhance the single well production, improve the gas recovery, and reduce the development cost, technical difficulties need to be overcome in the following four aspects: horizontal well technology and volumetric fracturing treatment, the building of underground gas storage, multi dimension development of multi layer gas reservoirs, and overall management of low production wells.