CAJ | 학술논문

在岩心刻度和常规测井标定基础上,根据FMI、EMI成像测井资料研究了塔里木盆地轮古东地区奥陶系良里塔格组和一间房组碳酸盐岩储层中溶洞的类型、特征及分布.将溶洞划分为斑点-斑块状溶洞、层状大洞、片状及网状缝洞等类型,提出了各类溶洞的成像测井识别标志.引入溶洞发育带的厚度、相对于古岩溶面的埋藏深度及分布密度(即溶洞发育带厚度占地层总厚度的百分数)等参数,研究了该区溶洞的空间分布.结果表明:90%左右的溶洞发育带的厚度都小于10 m,70%的溶洞发育带分布于良里塔格组顶部古岩溶不整合面以下200 m深度范围内;一间房组溶洞发育带的分布密度明显高于良里塔格组;总体上,自南东而北西,溶洞发育带的分布密度增大,指示古岩溶作用的强度朝北西方向逐渐增强.
재암심각도화상규측정표정기출상,근거FMI、EMI성상측정자료연구료탑리목분지륜고동지구오도계량리탑격조화일간방조탄산염암저층중용동적류형、특정급분포.장용동화분위반점-반괴상용동、층상대동、편상급망상봉동등류형,제출료각류용동적성상측정식별표지.인입용동발육대적후도、상대우고암용면적매장심도급분포밀도(즉용동발육대후도점지층총후도적백분수)등삼수,연구료해구용동적공간분포.결과표명:90%좌우적용동발육대적후도도소우10 m,70%적용동발육대분포우량리탑격조정부고암용불정합면이하200 m심도범위내;일간방조용동발육대적분포밀도명현고우량리탑격조;총체상,자남동이북서,용동발육대적분포밀도증대,지시고암용작용적강도조북서방향축점증강.
Calibrated by core and traditional well-log data, electrical image logs (FMI and EMI) are used to study the types, characteristics and distribution of paleocaves in the Ordovician carbonate reservoirs, including Lianglitage and Yijianfang Formations, in east Lungu area, Tarim Basin, Northwest China. The paleocaves are classified into three classes: speckled to patched caves, layered caves, sheet or reticular fractured caves. The identification of various caves on image logs is also discussed. To characterize the spatial distribution of paleocaves, quantitative parameters, including the thickness and the burial depth relative to paleokarst surface of a paleocave zone, and the distribution density of paleocave zones (defined as the percentage of the thickness of paleocave zones in that of a given stratal unit) are introduced. Results indicate that the thickness of about 90 percent of paleocave zones is less than 10 m, and 70 percent of paleocave zones occur within 200 m beneath the paleokarst surface (top of the Lianglitage Formation). The distribution density of paleocaves in the Yijianfang Formation is obviously much higher than that in the Lianglitage Formation. In lateral, the distribution density of paleocaves increases from southeast to northwest, which suggests that paleokarstification strengthened northwestwards.