元坝地区雷四段复杂岩性测井识别技术研究

Study on Complex Lithology Logging Identification Technology of the Fourth Member of Leikoupo Formation in Yuanba Area

摘要: 元坝地区雷口坡组岩性复杂，储层品质受地层矿物类型、岩性结构等因素控制。研究区岩心矿物分析资料较少，测井资料丰富，因此利用测井资料准确识别其岩性是进行储层高效评价、油气勘探开发研究的基础。本文综合分析了元坝地区雷四段地层岩性特征，分析了常规测井资料孔隙度曲线交会法在识别地层硅质矿物含量及黄铁矿等特殊矿物的局限性，综合利用了PE曲线排除重晶石泥浆等因素影响，定性识别白云岩；利用电成像测井资料分析地层岩性构造特征，识别复杂岩性；利用元素俘获测井资料，定量计算地层矿物含量百分数，准确绘制地层岩性剖面。最终采用各种综合测井资料相结合的原则，成功解决了元坝地区雷四段地层复杂岩性识别、储层识别等难题，为元坝地区雷四段风化壳气藏测井评价提供了技术支持。

Abstract: The lithology of Leikoupo Formation in Yuanba area is complex, and the reservoir quality is con-trolled by the mineral type and lithologic structure. The core mineral analysis data in the study area are few and the logging data are rich, so the accurate identification of its lithology by using logging data is the basis for efficient reservoir evaluation and oil and gas exploration and devel-opment research. In this paper, the lithological characteristics of the fourth member of Lei formation in Yuanba area are comprehensively analyzed; the limitations of the intersection method of porosity curve of conventional logging data in identifying the content of siliceous minerals and pyrite and other special minerals in the formation is analyzed, and the PE curve is comprehensively used to eliminate the influence of barite mud and other factors, so as to identify dolomite in a certain way; the lithologic structural characteristics of the formation are analyzed by using the electric imaging logging data, so as to identify complex ones; the element capture logging data to were used to quantitatively calculate the percentage of formation mineral content and accurately draw the formation lithology profile. Finally, by using the principle of combining all kinds of comprehensive logging data, the complex lithology identification and reservoir identification of the fourth member of Leikoupo Formation in Yuanba area are successfully solved, which provides technical support for logging evaluation of the crust of weathering gas reservoir in the fourth member of Leikoupo Formation in Yuanba area.