苏里格气田苏77区块气藏评价技术及应用效果

鄂尔多斯盆地苏里格气田主力气层下二叠统山西组山2段、山1段以及下石盒子组盒8段属于砂岩岩性气藏，具有“低孔、低渗、低丰度且非均质性强”等特点，气田规模开发存在较大难度。为此，在勘探程度较低的新区块规模开发前期，开展有针对性的评价工作，寻找含气相对富集区就显得尤为重要。苏77区块在开发前期针对区块面临的地震测网稀、井控程度低、区块内尚未提交任何级别储量、局部存在富水区、单井产能不落实、区块地质认识有待进一步深化等主要问题，开展了地震、评价井及开发试验等方面的开发评价工作。采用“地震-地质相结合”的技术思路，通过二维地震测线控制，结合评价井钻探及沉积相、成岩作用、储层综合评价研究成果，评价河道发育带，预测有效储层分布，进而筛选出含气富集区。2010-2011年在筛选的含气富集区内集中进行产能建设，完钻开发井Ⅰ+Ⅱ类井比例大幅度提高，开发效果良好。该区块开发实践表明所运用的开发前期评价技术行之有效，值得同类型气藏开发评价借鉴。

Gas reservoir evaluation techniques and their application in Block Su-77 of the Sulige Gas Field

The 1st and 2nd members of the Permian Shaanxi Formation and the 8th member of the Permian Shihezi Formation,as the major gas pay zones of the Sulige Gas Field,Ordos Basin,are sandstone gas reservoirs characterized by low porosity,low permeability,low abundance,and strong heterogeneity.Therefore,it is challenging for the commercial development of this field.It is particularly important to find sweet spots through evaluation at the initial stage of scaled development of new blocks with relatively low exploration maturity.Therefore,in the early period of the development of Block Su-77,various problems were thoroughly analyzed such as sparse seismic grid,low degree of well control,no registered gas reserves,local occurrence of water layers,uncertain single well productivity,and unclear geological conditions.On this basis,the development evaluation of this block was performed through seismic acquisition and interpretation,exploratory well drilling,and development pilot tests.Additionally,seismic data and geological data were integrated to identify channel sandbodies and predict effective reservoirs,so as to delineate the gas zones with high potential.The proportion of development wells of typeⅠand Ⅱ in the total wells drilled in 2010 and 2011 increased by a big margin.The results show that these evaluation techniques are effective and can be applied to other similar gas reservoirs.