X射线荧光岩屑识别技术研究

【作者】 李春山；

【导师】 孙卫；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2010， 博士

【摘要】 在石油钻井施工中,准确获取岩性资料是录井的基本任务,是及时建立地层剖面、准确评价油气层性质、正确预测下部地层的前提,也是指导钻井生产正常运行的最基础的工作。然而,目前PDC钻头的使用、空气钻井等钻井工程工艺发展,使常规的录井方法难以准确识别岩性,水平井地质导向给录井的岩性识别和地层划分提出了更高的要求。X射线荧光分析技术,可对样品中的元素进行定性和定量分析。本文在鄂尔多斯盆地北部上古生界沉积特征分析基础上,确定了X射线荧光录井的元素组合,分析岩屑中的元素包括Mg、Al、Si、Ca、Fe、Mn、K、Cl、S、Ti、P、Ba等12种元素,这些元素占地壳物质总量的99.48%以上,因此具有代表性。这些元素基本反映了石油地层中主要矿物的指示元素。本文对鄂尔多斯盆地塔巴庙区块26口井,近20000个岩屑样品进行了X射线荧光分析,并对分析结果进行了深入研究,结果表明,元素含量变化与岩性变化具有很强的相关性。X射线荧光分析技术可作为录井岩性识别和地层划分的新手段,同时定量的元素分析数据为岩性、物性、地层的定量解释和定量评价提供了技术支持。通过大量室内分析实验和随钻录井,形成了X射线荧光录井仪器的标定和校验方法,建立了X射线荧光录井技术工艺流程；并通过认真研究,提出了较完善的基于X射线荧光录井的岩性识别及解释方法。研究成果在鄂尔多斯盆地南部、塔里木盆地、二连盆地、渤海湾盆地等地区对其研究成果进行了广泛的验证,进一步完善了该项新的录井方法。同时,利用X射线荧光录井这一新的技术方法,及时准确地进行岩性、地层的识别和正确解释,正确指导了钻井生产,形成了较为成熟的X射线荧光随钻录井技术。研究证明,X射线荧光分析技术应用于随钻岩屑录井是完全可行的,X射线荧光分析获得的丰富的元素信息,为准确的岩性识别和正确的地层判断提供了强有力的技术支持,有效地解决了PDC钻头、气体钻井等钻井条件下的录井技术瓶颈问题,并且随着研究的深入,其在储层物性评价、储层流体性质识别、沉积相研究等诸多方面的作用也初步展露。X射线荧光录井技术为“定量化”录井技术的发展迈出了坚实的一步。更多还原

【Abstract】 During drilling operations it is essential to acquire lithologic informatioin which is needed to establish formation top, evaluate reservoir, predict formations to be penetrated, and guarantee normal performance of drilling operations. However, due to use of PDC bits and air drilling technique, accurate lithologic identification is difficult to obtain through conventional mudlogging. Geosteering technique also requires even more accurate lithologic identification and formation description.X-ray fluorescence can be utilized to analyze elements of rock samples both qualitatively and quantitatively. On the basis of analysis about upper Paleozoic deposition in north of Eldos Basin, the combination of elements was determined by the X-ray fluorescence technique, which includes Mg, Al, Si, Ca, Fe, Mn, Cl, S, Ti, P, and Ba. The above elements take up 99.48% of total earth crust element contents, and thus can be regard of being representative. The elements can basically reflect the indicating elements existed in petroleum formations. In this paper, about 2000 rock samples from 26 wells located in Tabamiao block of Eldos Basin were analyzed with X-ray fluorescence, and insight investigation was conducted to the analysis result. It is found that a strong correlation exists between element content variation and lithology, and X-ray fluorescence analysis technique can be used as a new means for lithologic identification and formation description, and the qualitative element data can provide technical support for quantitative interpretation and evaluation about lithology, physical property, and formation.The calibration of X-ray fluorescence mudlogging instrument was performed with a great deal of lab tests and LWD, and X-ray fluorescence mudlogging process was established. Lithological identification and interpretation method was proposed through detailed study, which had been extensively applied in south of Eldos Basin, Tarim Basin, Erlian Basin, and Bohai Bay Basin. Gradual improvement was made throught application. It has been developed into a mature LWD technique which can be used to determine lithology, describe formation and provide guidance for drilling operations.It is proven that X-ray fluorescence technique is quite feasible to be used in LWD. The element content data obtained from such a technique can provide technical support for accurate lithologic identification and formation determination. The long-term mudlogging problems encountered while using PDC bits and air drilling technique can be solved. Moreover, it may be found through future further research that X-ray fluorescence technique can be used for reservoir evaluation, reservoir fluid identification, and sedimentary facies study. X-ray fluorescence technique is a solid step forward towards "qualitative" mudlogging technology.更多还原