【作者】 王志战；

【导师】 周立发；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2006， 博士

【摘要】 异常压力是含油气盆地普遍存在的一种现象。异常压力尤其是异常高压直接关系到钻井安全,从而关系到人身、财产安全,关系到油气的勘探进程。做好异常压力预监测工作对于发现油气藏、设计井身结构、保障钻井安全、保护油气层具有十分重要的意义。在深入分析异常压力成因机制及其分类的基础上,对济阳坳陷异常压力的成因与分布展开研究,对前人提出的水热增温、构造抬升超压机制和差异负荷负压机制提出质疑,并提出了新的成因机制。异常压力对成藏要素的影响以及这些影响在勘探、钻探手段上的响应特征,是进行异常压力预监测的理论基础。根据异常高压与异常低压成因的逆向性,超压和负压都是可以预测的,只是响应特征相反。钻前预测,针对济阳坳陷勘探程度高及深层勘探地震预测精度低的特点,提出了基于三维可视化及平面数据分析的地质统计分析方法;随钻预测,针对dc指数等的适用性问题,实现了不同压力成因条件下的预监测方法组合,拓宽了压力预监测的适用范围;而对趋势线的选择,则从层序地层学的角度,对不同层位的趋势线进行了确定。同时将离子色谱和核磁共振录井新技术应用于异常压力随钻预监测,取得了良好的应用效果;同时,推导出基于核磁孔隙度的破裂压力准确计算方法。基于异常压力成因的综合性、响应特征的多解性,应采用多种检测手段,进行综合预监测。更多还原

【Abstract】 Abnormal pressures widely exist in oil and gas basins. Abnormal pressures, especially overpressures directly relate to drilling safety, furtherly relate to personal safety and property loss, and affect the prospecting program of oil and gas. It’ s very important for hydrocarbon reservoir finding, casing program design, drilling safety guarantee and hydrocarbon reservoir protection to do abnormal pressure prediction and detection well. On the basis of deeply analysis of causal mechanisms of abnormal pressure and their classification, the generation and distribution of abnormal pressure in Jiyang Depression get be studied, and such overpressure causal mechanisms as aquathermal expansion and tectonic uplift proposed by Li Pilong et al(2004) and underpreesure causal mechanisms are argued against, in the meantime, new causal mechanisms get be proposed. The abnormal pressures effects on elements of hydrocarbon reservoirs and their responses in exploration and drilling instruments are the basis of before and while drilling prediction and detection for overpressures. Both overpressure and underpressure could be predicted according to opposite response characteristics, because of their opposite causal mechanisms. As for before drilling prediction, a new method called Geological statistics and analysis has been proposed by study, due to the low seismic Signal-to-Noise in deep layer and high exploration degre. As for the while drilling prediction and detection, dc exponent is the most common method because of its on-line, continuity and quantification, The basic reasons that affect its application results are the selection of trend line and appliance conditions. The methods combination and trend line determinated by sequence stratigraphy studied in this dissertition could solve such two questions. MR-ML could provide direct and relative precision porosity for fracture pressure caltulation, besides used for pressure prediction and detection. As for an given area, the overpressures are always caused by more than one mechanisms, and the reponses also have multiresolutions. So many abnormal pressure determination measures should be adopted to synthetically predict and detect abnormal pressures.更多还原