信息缺失条件下的海上区块地应力三维分布综合研究

Comprehensive Investigation on the 3D in-situ stress with limited information for the offshore region

地应力是油气勘探开发过程的重要参数.受到设备、技术水平和自然条件等因素的影响,某些区块勘探钻井信息获取困难;同时存在深水钻井数量少、取心代价高、地应力实测难度大、成本高等困难,使得新勘探区块的地应力相关信息缺失严重、认识程度还比较低.针对上述问题,本文在信息缺失条件下利用多种方法开展地应力研究:通过单井计算建立单井地应力一维剖面;结合区域地质概况,运用Petrel软件和Abaqus软件,利用空间插值法和有限元数值模拟法分别建立地应力模型,通过一维单井地应力计算重构三维地应力分布.通过分析对比发现,利用有限元数值模拟法建立的模型与实际结果相比误差较小,地应力三维分布趋于合理,该研究方法能够为该区块的地应力研究提供一定的参考意义.

In-situ stress is an important parameter in oil and gas exploration and development. Influenced by factors such as equipment, technical level and natural conditions, it is difficult to obtain exploration and drilling information in some blocks;At the same time, there are many difficulties in deep water drilling, high coring cost, difficulty in measuring in situ stress, high cost, etc., which makes the lack of information about in-situ stress in the new exploration block serious and low level of recognition. In view of the above problems, this paper uses a variety of methods to conduct in-situ stress research under the condition of lack of information: Established the Single well in-situ stress one-dimensional profile by single well calculation;Combined with the regional geological profile, using Petrel software and Abaqus software, using spatial interpolation method and finite element numerical simulation method to establish the in-situ stress model, through the one-dimensional single-well in-situ stress calculation to reconstruct the three-dimensional in-situ stress distribution. Through analysis and comparison, it is found that the model established by the finite element numerical simulation method has less error than the actual results, and the three-dimensional distribution of in-situ stress tends to be reasonable. This research method can provide a certain reference significance for the study of in-situ stress in this block.