四川盆地深层海相碳酸盐岩气藏开发技术进展与发展方向

Progress and development direction of technologies for deep marine carbonate gas reservoirs in the Sichuan Basin

近年来,深层海相碳酸盐岩气藏成为四川盆地常规天然气增储上产的重要领域,但由于该类气藏成藏条件复杂、埋藏深且气水关系复杂,其高效开发面临着巨大的挑战。为此,通过剖析该盆地深层海相碳酸盐岩气藏开发历程,结合深层碳酸盐岩气藏的开发特点与实践,总结梳理了专项技术,并指出了下一步的攻关方向。研究结果表明:①四川盆地深层海相碳酸盐岩气藏的储量规模差异大、类型多,储层品质差、非均质性强,边、底水活跃,且原料气普遍含酸性气体,同时开发井多位于山地,钻遇地层纵向上展布复杂;②四川盆地已形成了一系列专项技术——深层低缓构造强非均质气藏精细描述技术、小尺度缝洞发育的有水气藏治水优化技术、深层复杂气井钻完井及增产工程技术、含硫气藏清洁安全开发配套技术,支撑了该盆地特大型海相碳酸盐岩气藏的高效建产及优化开发;③随着盆地内碳酸盐岩气藏开发开始向超深层的复杂构造带气藏转移,针对该类气藏的构造精细描述和薄储层预测技术、跨尺度数值模拟技术、钻完井及采气工程技术是下一步的技术攻关方向。结论认为,所形成的深层海相碳酸盐岩气藏高效开发专项技术为中国石油西南油气田建成百亿立方米特大型气田、实现天然气产量跨越式增长提供了有力的支撑,相关研究成果可以为国内外深层海相碳酸盐岩气藏的开发提供借鉴。

In recent years,deep marine carbonate gas reservoirs has become an important field in increasing conventional gas reserves and production in the Sichuan Basin.Due to complex hydrocarbon accumulation conditions,great burial depth and complicate gas-water relation,however,this type of gas reservoirs faces huge challenges to realize efficient development.In this paper,the development history of deep marine carbonate gas reservoirs in the Sichuan Basin was analyzed.Then,based on such development characteristics and practices,special technologies were summarized.Finally,the research direction for the coming years was pointed out.And the following research results were obtained.First,the reserves of the deep marine carbonate gas reservoirs in the Sichuan Basin vary greatly in scales and types.The reservoirs are of poor quality and strong heterogeneity with active edge and bottom water.The raw gas generally contains acidic gas.What's more,most development wells are located in mountainous areas,and drilled formations are complicated in vertical distribution.Second,special technologies have been formed in the Sichuan Basin,including the fine description technology for strong-heterogeneity gas reservoirs in deep low-gentle structures,the optimized water control technology for the water-bearing gas reservoirs with developed small-scale fractures and vugs,drilling,completion and stimulation engineering technologies for deep complicated gas wells,and the support technology for clean and safe development of sulfur-bearing gas reservoirs,so as to provide support for the efficient productivity construction and optimized development of giant marine carbonate reservoirs in the Sichuan Basin.Third,as the development of the carbonate gas reservoirs in the Sichuan Basin begins to convert into the gas reservoirs in ultra-deep complex structures,the next direction of technological research is the fine structure description and thin reservoir prediction technique,across-scale numerical simulation technique,drilling and completion and gas production engineering technique for deep marine carbonate gas reservoirs.It is concluded that these special technologies for the efficient development of deep marine carbonate gas reservoirs provides powerful support for the PetroChina Southwest Company to build up giant gas fields with the reserves of tens of billions of cubic meters and realize the leaping growth of gas production.The research results can provide valuable technical reference for the development of deep marine carbonate gas reservoirs at home and abroad.