Abstract:

The Enping formation of Y structure in block X in the east of the South China Sea develops a lake bottom fan deposit formed by the collapse of large sand rich braided river delta front sand body, which is vertically superimposed in multiple stages and has good superposition. The fluid properties in the block are complex and diverse, and there is a common phenomenon of gas production from oil reservoir and oil production from gas reservoir. The oil and gas layers have similar characteristics in logging data, which greatly increases the difficulty of fluid phase identification in the block, thereby providing certain difficulties to the comprehensive interpretation of logging. In view of the complexity of fluid properties in the study area and the difficulty of accurately identifying oil and gas reservoirs by using conventional gas logging anomaly multiple method, gas ratio method, three?dimensional and geochemical logging data, through the optimization of hydrocarbon component interpretation method based on gas logging, this paper came to the conclusion that Bar chart method and star chart method can quickly and effectively identify oil and gas reservoirs in this block. At the same time, the field application shows that the Bar chart and star chart fluid interpretation and evaluation method based on the difference of hydrocarbon component characteristics in gas measurement can quickly and accurately interpret and evaluate the complex fluid in block X reservoir. The results of interpretation and evaluation while drilling using this method are consistent with the results of testing, and the coincidence rate is more than 87%, which provides a reliable basis for the later reserve evaluation of the oilfield.

Key words: Method optimization, Hydrocarbon composition, Bar chart method, Star chart method, Evaluation method

摘要：

南海东部X区块Y构造恩平组发育大型富砂辫状河三角洲前缘砂体滑塌形成的湖底扇沉积，垂向上多期次叠置且叠合性较好。区块内流体性质复杂多样，普遍存在油层出气和气层出油现象，油层和气层在录井资料上表现特征相似，因此大幅度增加了该区块的流体相态识别难度，从而给录井综合解释带来了一定的困难。针对研究区流体性质复杂且利用常规气测异常倍数法、气体比率法、三维及地化录井资料无法准确识别油气层的难点，对气测烃组分解释方法进行优选，结果表明，Bar图法和星型图法可快速有效地识别该区块油气层。现场实际应用表明，基于气测烃组分特征差异的Bar图和星型图流体解释评价方法，可快速准确地解释评价X区块储层内复杂流体。利用该方法在随钻过程中的解释结论与测试求产结果相符合，符合率达到了87%以上，为油田后期储量的评估提供了可靠依据。

关键词: 方法优选, 烃组分, Bar图法, 星型图法, 评价方法