川东地区长兴组生物礁录井识别

四川盆地川东地区二叠系长兴组生物礁碳酸盐岩的储集条件好，油气资源丰富。为此阐述了川东地区二叠系海相碳酸盐岩生物礁的地质、构造特征；从地质录井的角度全面论述了该区生物礁云岩在钻井勘探中的厚度变化、岩性特征、生物特征、钻速变化，以及油、气、水、漏显示等情况；总结了如何根据上述显示快速、准确地判定已钻遇生物礁云岩，以利于指导钻探工作，保护好川东地区二叠系长兴组生物礁碳酸盐岩的油气层，提高勘探效益。

LOGGING RECOGNITION OF CHANGXING FORMATION BIOHERM IN EASTERN SICHUAN BASIN

The Upper Permian Changxing Formation biohermal carbonates in eastern Sichuan Basin have good reservoir conditions and are rich in petroleum resources. This paper introduces the geologic and structural features of the Permian marine biohermal carbonates in the study area, discusses the geologic thickness, lithologic properties, biological features, and change of drilling rate, as well as shows of oil, gas, water and lost circulation, and summarizes the methods to rapidly and accurately recognize and determine bioherms encountered according to the above mentioned indicators. ① If layer thickness reduces significantly and no shale or shaly limestone are encountered at the bottom when drilling in the Feixianguan Formation, it is highly possible that bioherms are developed in the Changxing Formation. ② It is highly possible of encountering bioherms when the rocks in Changxing Formation become lighter in color, getting purer in quality, without containing any siliceous and chert nodules but with rich bioclasts instead, and meanwhile drilling rate of the same bit gets significantly higher, and oil/gas shows are also identified at the moment. ③ Correct conclusions can be drawn only through comprehensive analysis of all the above mentioned indicators, so as to avoid drilling failures.