【作者】 王群嶷；

【导师】 赵鹏大；

【作者基本信息】 中国地质大学（北京） ， 资源产业经济， 2009， 博士

【摘要】 大庆外围低渗透油田扶杨油层约有3.07亿吨难采储量资源,这样资源经济有效开发动用都需要整体压裂投产完井才能实现。地应力是油气田勘探开发、油气井工程设计和施工的重要基础资料之一。目前获得某点地应力最直接的方法仍然是地应力测量,然而由于经费等条件限制,实际开展的测量工作很有限,而离散的实测点只能反映局部位置地应力状态,数值模拟方法是区域地应力场定量研究的有效手段,量化三维地应力场是经济有效开发动用低渗油田难采储层油气资源重要的支撑理论基础。本文以石油地质学、物理测井、岩石力学、钻井工程、储层改造、油气藏工程学等多学科理论和方法为指导;按照地应力测量、地质构造研究、地应力场有限元优化反演到应用研究的系列化技术路线,开展三维地应力场有限元数值模拟及地应力的应用研究工作,论文在基础理论探讨、技术方法、软件编制及综合应用等方面,均有较明显的突破,取得了一些有意义的新认识。首先,针对当前数值模拟工作自动化水平低且精度不高的问题,基于数学最优化理论和有限单元法,将地应力场反演过程抽象成数学最优化问题,建立了三维地应力场有限元约束优化反演法;利用ANSYS有限元系统的二次开发功能,研发出基于ANSYS的三维地应力场有限元约束优化反演技术;编制地应力场后处理分析程序,实现三维空间任意截面或曲面上应力矢量的可视化,给出地应力大小和方向受断层扰动区域的范围以及受扰动程度,显著提高了三维地应力场后处理分析功能。其次,从当前地应力场数值模拟存在的缺陷出发,探讨了两种断层介质的力学模型,即:非均质连续介质模型和非连续介质模型,提出断层介质力学模型的选用要遵循两条原则,即:满足研究目的并且简易可行。再次,以岩石力学实验及地应力岩心测量为基础,利用开发的三维地应力场有限元约束优化反演技术,对松辽盆地三肇凹陷树25区块的地应力场进行了综合研究。一方面建立了复合断层交互影响下树25区块的三维地应力场分布规律,重点分析了地应力状态受断层扰动范围以及受扰动程度,总结了断层对地应力场的“动态”影响规律。另一方面,通过对树25区块几口井地层力学参数和地应力的测井解释,建立了动静态弹性参数、破裂压力、出砂指数等参数以及地应力的纵向分布剖面。最后,应用树25区块三维地应力场数据分布规律,进行构造裂缝分布预测、水力压裂优化设计、出砂预测和注水井网布置等应用研究,并有针对性地量化提出了相应的低渗透油田开发方案改进措施。更多还原

【Abstract】 There are 30700×104 t low permeability oil resources in Daqing Oil Field. Economical effective development low permeability oil and gas resources need to use 3-D in-situ stress field.The state of in-situ stress field is one of the important and basic data for oil and gas exploration and development and for design of well drilling engineering. Although the in-situ stress measurement is still the most directly method for in-situ stress determination to this day, but in fact, the actual measurements for in-situ stress are very limited because of the costly expense and other conditionality. It is a fact that the distribution of in-situ stress field can not be generated by some discrete measuring points. Three-dimensional numerical simulation is an effective tool for research on regional in-situ stress field and it greatly attracts the attention of the scientists all over the world.Taking the petroleum geology, the geophysical well logging, rock mechanics, the well drilling project, the oil gas reservoir transformation, the oil gas pool engineering and the mufti-disciplinary theory and the method as the instruction, according to the research approach and procedure which include in-situ stress measurement, geological structure, inversion of in-situ stress field by finite element method and application of in-situ stress, 3-D numerical simulation of the in-situ stress field and its application in oilfield development has been systematic studied in this thesis. Some new outcomes and cognition have been acquired during the research on basic theory, technology, software development and application.Firstly, In view of the low degree of automation and accuracy of the in-situ stress numerical simulation, the optimization theory has been introduced to the inversion of 3-D in-situ stress field. And a method called constrained optimization inversion of 3-D in-situ stress field has been established with the finite element method (COFEMI), which has been developed based on the second development technique of ANSYS. Much research on improving post-treatment of 3-D in-situ stress field numerical simulation has been done. And a software package has been compiled which can give vector of in-situ stress in the form of contour diagrams in any special observation planes .And the software can also point out the area where the in-situ stress has been effected by faults and the influential level for different locations. The software has greatly increased the automation for 3-D in-situ stress field analysis, and it can also realize visualization of the results. Secondly, aiming at overcoming the deficiency of the in-situ stress numerical simulation, two mechanical models of fault have been studied in the thesis, including the model of heterogeneous continuous medium and the model of the discontinuous medium. The thesis has proposed some principles, summarized as feasibility and simplification, which should be followed when selecting the mechanical model of faultThirdly, based on rock mechanical tests and in-situ stress core tests, the thesis has systematically studied the in-situ stress of block SHU-25 in Sanzhao depression, Songliao basin. The 3-D in-situ stress field under the effect of faults has been established, and the thesis has put its emphasis on the area where the in-situ stress has been affected by faults and the influential level analysis for different locations. The effect regularity of faults on in-situ stress has been summarized. Also, the longitudinal distribution of the mechanical properties and in-situ stress, which include dynamic and static elastic parameters, fracture pressure, sand production index et al, has been generated using the well logging data.In the end,based on the 3-D in-situ stress field by the COFEMI method and the longitudinal distribution calculated using Logging Data. The application of in-situ stress in oil and gas development has been discussed, including fracture prediction, optimization procedure for hydraulic fracturing, sanding prediction, flooding well network optimization et al. The thesis has proposed some innovative approaches for improving oil and gas development in this block.更多还原