松辽盆地北部深层火山岩气藏勘探开发关键技术

Key technologies for exploration and development of deep volcanic gas reservoirs in northern Songliao Basin

松辽盆地北部徐家围子断陷火山岩气藏是徐深气田的主力气藏,具有岩性多样、储层非均质性强的特点,面临气藏富集规律不清、优质储层预测难、气井产能和井控储量变化规律复杂、剩余气挖潜难度大等一系列技术难点和挑战。通过开展火山岩气藏成藏演化过程分析、火山岩喷发期次描述、有效储层预测、井控储量评价、剩余潜力描述等工作,攻关形成了火山岩气藏成藏评价、三级火山体精细刻画、动态储量评价、剩余潜力评价及挖潜等技术。建立了“低渗增长型+高渗稳定型”2类动态储量模式及动静结合“六参数”挖潜技术政策界限,落实了烃源岩生气期及气藏成藏期,明确了气藏富集受源岩、断裂、储层、盖层四因素的联合控制,实现了对火山岩储层内部结构的精细表征,搞清了2类气井动态储量增长规律,形成了不同类型剩余气的挖潜技术对策。基于火山岩气藏一系列勘探开发关键技术的创新,徐深气田的天然气产量逐年攀升,形成的系列技术在大庆油田已得到全面推广应用,并取得了明显效果,有效支撑了大庆油田天然气产量的持续稳定增长。研究成果可为同类型气藏的勘探开发提供有效的技术指导。

Volcanic gas reservoirs in Xujiaweizi Rift of northern Songliao Basin are the main reservoirs of Xushen Gas Field,characterized by diverse lithology and high heterogeneity of reservoirs,and facing a series of technical difficulties and challenges such as unclear understanding of gas enrichment laws,difficult prediction of high-quality reservoirs,complex variation laws of gas well productivity and well-controlled reserves,and difficulty in tapping remaining gas potential.Analysis of evolution process of volcanic gas accumulation,description of volcanic eruption stages,prediction of effective reservoirs,evaluation of well-controlled reserves and description of remaining potential are performed to develop techniques including accumulation evaluation of volcanic gas reservoirs,fine characterization of three-orders volcanic bodies,dynamic reserves evaluation and remaining potential evaluation and tapping.2 types of dynamic reserves models of“low permeability growth type+high-permeability stable type”are clarified,as well as policy limits for potential tapping technology of combining dynamic and static“6 parameters”.Gas generation period of source rock and gas accumulation period are determined,gas enrichment is clarified to be controlled by 4 factors of source rock,fracture,reservoir and cap rock,fine characterization of internal structure of volcanic rocks is realized,2 types of dynamic reserves growth laws of gas wells are clarified,and potential tapping technical solutions for different types of remaining gas are formed.Based on a series of key technical innovation for exploration and development of volcanic gas reservoirs,natural gas production of Xushen Gas Field increases year by year.The series of technology is popularizing applied in Daqing Oilfield with significant results,effectively supporting continuous and stable growth of natural gas production in Daqing Oilfield.The research provides effective technical guidance for exploration and development of similar type of gas reservoirs.