台南凹陷岩石热解录井影响因素及对策

Affecting factors and countermeasures of rock pyrolysis logging in Tainan Sag

PDC钻头和混油钻井液的广泛使用造成岩屑细小混杂且受到一定程度的污染,给以岩屑为分析对象的岩石热解录井储集层解释评价带来一定困难。在吐哈盆地台南凹陷岩石热解录井中,通过对钻井、钻井液、分析仪器和样品放置时间4项影响因素的分析,认为钻井和钻井液为主要影响因素,应采取相应措施予以消除,而分析仪器和样品放置时间为次要因素且在一定程度上可控。为消除主要影响因素,首先,基于确保分析样品代表性的角度,探讨了采用岩样对比分析法、样品二次清洗后再分析等手段可排除部分干扰因素,提高岩石热解录井数据的准确性;其次,从形成准确的储集层录井解释评价结论的角度入手,采用岩石热解录井与其他录井相结合的综合解释法,或通过岩心与岩屑热解分析含油气总量的差值法,均可最终消除各种因素对岩石热解录井评价的影响。以台南凹陷为例,对岩石热解录井影响因素的分析及对策的系统阐述,对于其他地区同样具有借鉴与指导意义。

The widespread use of PDC bit and oil emulsion drilling fluid caused the cuttings to be fine and mixed with a certain degree of pollution,bringing some difficulties on rock pyrolysis logging reservoir interpretation and evaluation which takes cutting as the analysis object.During rock pyrolysis logging in Tainan Sag,Tuha Basin,through the analysis on four affecting factors of drilling,drilling fluid,analytical instrument and the standing time of the sample,the authors thought that drilling and drilling fluid were the main affecting factors,and corresponding measures should be taken to be eliminated,while the analytical instruments and the standing time of the sample were the secondary factors and can be controlled to a certain extent.To eliminate the main affecting factors,first of all,based on ensuring that the analysis samples are representative,the authors discussed to use core sample contrast analysis,re-analysis after the sample was washed for two times and other methods to eliminate some interference factors and improve the accuracy of rock pyrolysis logging data.Secondly,setting from forming the accurate conclusions of reservoir mud logging interpretation and evaluation,using comprehensive interpretation method of combining rock pyrolysis logging with other mud logging technologies,or the difference method of the total oil and gas between core pyrolysis analysis and cutting pyrolysis analysis,can eliminate the influence of various factors on the rock pyrolysis logging evaluation.Taking Tainan Sag as an example,the systematic elaboration about analysis and countermeasures of the factors of affecting rock pyrolysis logging also has reference and guiding significance for other areas.