【作者】 王威；

【导师】 刘全稳； 韦雨；

【作者基本信息】 西南石油大学 ， 矿产普查与勘探， 2013， 博士

【摘要】 渤中A油田位于渤海南部海域,渤南凸起西侧倾伏端,构造上北临渤中凹陷,南靠黄河口凹陷,呈现由断裂控制的披覆半背斜构造形态。由于南北侧分别紧邻黄河口和渤中两个富生烃凹陷,并存在与油气运移相匹配的断层活动,该构造具备了极为优越的油气地质条件。同时,渤中A油田具有油藏类型复杂,含油层系多、油水关系复杂、储层连通性差等特点。复杂的油藏地质特征给准确预测油气储量以及制定整体开发方案带来很大困难。因此,系统精细地解剖油气藏及内部结构,揭示油气分布规律,建立储层三维空间定量分布模型,进一步真实、直观地再现地下地质结构及储层特征,定量描述储层参数的空间非均质性,设计数值模拟网格系统,将精细的地质模型转换为油藏数值模拟静态模型,对渤中A油田整体开发方案的优化设计调整具有重要意义。采用多学科综合一体化原则,以科学的地质理论及三维地质建模方法为依据,充分利用地震、钻井、测井、试井及分析化验等原始资料,在基础地质、测井综合解释、地震储层横向预测等研究基础上,应用先进的三维可视化地质建模软件——PetrelTM,建立渤中A油田高精度的确定性和随机性三维地质模型,并在一定的控制条件下,模拟出各种可能的变化过程,然后根据具体目的进行选择,得出最合理的地质模型,并在模型粗化的基础上进行油藏数值模拟研究。以更新产量预测指标,指导开发方案的制定,开展全面的、深入细致的研究。主要研究成果与认识如下：1)区内主要发育着曲流河沉积、辫状河沉积、三角洲沉积和冲积扇沉积等多种沉积类型,砂泥岩沉积类型多样。明化镇下段发育曲流河环境下的点坝、天然堤、泛滥平原微相；馆陶组发育辫状河沉积环境下的心滩、溢岸沉积、泛滥平原微相；东营组发育三角洲沉积环境下的分流河道及河口坝微相。2)应用新井解释分析资料,验证和调整评价阶段乃至开发方案实施阶段储层描述所应用的地质知识,更新地质模型,描述不同类型油藏的储层特征,表征油气水分布及定量描述储层参数的空间非均质性,实现三维地质建模。通过对多个等概率随机模型进行优化排队,评价影响储层三维地质模型的不确定因素,进行地质模型优化。优选储层、储量拟和与地质储量相近的一组模型粗化提供给油藏数值模拟器。3)油藏类型复杂,含油层系多,单层油层厚度薄,含油井段长,达1000多米,压力差异大；而且Nm1、Ng01、Ng02油气层储量较小,大多数为孤立油层或油气层,初期开采价值不大。为此确定合理的开发策略是,先动用开采NgⅠ、NgⅡ、Ngm、NgⅣ、Ed1和Ed2六个油组；Nm1、Ng01、Ng02油层以及气层原则上初期不射开,而等到后期产能递减阶段上返回采。4)理论公式计算以及数值模拟研究表明,允许合理的流动压力10MPa,临界流压6MPa；合理生产压差控制在2MPa以内,最大不宜超过8MPa。5)油层层内、层间连通性差,上下盘油水关系复杂；而且该油田水体能量较充分,地层压力下降缓慢。注水开采和衰竭开采的数值模拟对比表明,注水提高采收率的效果很小,与衰竭式开采方式的采收率接近,应进行衰竭式开采。6)对影响开发效果的不确定因素,比如数模网格尺寸、岩石总体积、渗透率、纵向连通性、岩石压缩系数、束缚水饱和度、油水过渡带高度和表皮系数等因素进行了敏感性分析评价,考虑敏感因素对开发水平所造成的影响。7)利用建立的地质模型,设计优化投产方案七个。模拟预测结果显示,提液方案的开采效果均好于不提液方案的开采效果；采取滑套依次打开的工作制度,层间干扰在一定程度上减小了,稳产期也有所延长。筛选优化投产方案为：初期采油速度接近3%,开采18年后的采出程度11.7%。8)数值模拟结果表明,该油田的采出程度较低。分析主要有以下原因：(1)孤立油藏多,油水关系复杂、动用程度低；(2)离边底水的距离近,水淹快；(3)含有油层系多,单层油层厚度薄,含油井段长,压力差异大,窜流和层间干扰严重。通过建立渤中A油田高精度三维地质模型,包括三维地质结构模型、确定性、随机性沉积相模型、相控岩石物理属性模型、粗化三维地质模型,并在一定的控制条件下,模拟出各种可能的变化过程,然后根据具体目的而进行选择,得出最合理的地质模型,并在模型粗化的基础上进行油藏数值模拟研究,更新产量预测指标,指导开发方案的制定,并为渤中A油田开发方案的优化调整提供技术支持。更多还原

【Abstract】 Bo zhong A Oilfield is located in the south Bohai and the block is located in the west pitch side of Bonan Uplift. It adjoins Bozhong Uplift on the north and nexts to Huanghekou Sag on the south. The structure presents draping semi anticline pattern which is controlled by fault. There are two rich hydrocarbon generation depression next to Bozhong A Oilfield and the faulting and oil-gas migration exist meanwhile, which make the structure have superior geological conditions. Moreover, Bozhong A Oilfield has some characteristic, such as complicated reservoir type, many oil-bearing strata, complex oil-water relationship, bad reservoir connectivity. Complex geologic feature brings lots of difficult to calculate oil and gas reserves and formulate whole development project. Therefore, describing reservoir and inner structure subtly, revealing the law of oil and gas distribution, constructing3D quantitate distribution model of reservoir, reappearing geologic structure and reservoir characteristic truly and visually, describing non-homogeneity of reservoir parameter, designing numerical simulation net system, transforming the elaborate geological model into numerical simulation static model, they have important significance to optimize and adjust development program of Bohai A Oilfield.Adopting multidisciplinary integration principle, according to geological theory and3D geological modeling theory, utilizing seismic, drilling, logging, testing and analytical test data, based on research of geology, logging data comprehensive explanation, reservoir prediction, advanced3D visual geology modeling software, which is called Petrel TM, is used to construct elaborate certainty and randomness3D geology model. In some certain condition, probable change process is confirmed, then according to the specific purpose, the most reasonable geological model is selected and obtained. On the basis of selected model, numerical simulation research can be carried out, output predict target is updated, formulating the development strategy can be guided, the whole and deep study can be carried out. The main research results and cognition follows:1) Meandering stream deposit, braided river deposit, delta deposit and alluvial fan deposit develop in research area. The type of sand-mudstone are varied. Point bar, natural levee, flood plain of meandering stream environment develop in the bottom of Minghuazhen Strata; river island, overflow facies, flood plain of braided river deposit environment develop in Guantao Strata; distributary channel, estuary dam of delta deposit environment develop in Dongying Strata. 2) By ranking some equal probability model, the uncertain factor of3D geological model is evaluated and the model is optimized. The optimized reservoir stratum should be distributed reasonably. A set of model, in which reserves fitting and geological reserve are closely, should be provided to reservoir numerical part.3) The reservoir type is very complex and there are many oil-bearing series in the reservoir, but the single pay sand is very thin. Oiliness well section is long and it is up to1000m and pressure difference is big; moreover, the reserve of Nmi, Ngo1, Ngo2is relative small, many of which are isolate pay sand or oil and gas reservoir. The value of exploitation is not high in initial stage. Therefore, the rational development strategy is confirmed, producing Ngi, NgⅡ, NgⅢ, NgⅣ, Ed1and Ed2first; Nml, Ngo1, Ngo2are not perforated early stage in principle, when going into productivity decreasing stage, corresponding strata should be perforated to produce.4) The calculate result based on theory formula and numerical simulation research indicate that the rational flow pressure is10MPa, critical flow pressure is6MPa, rational productive pressure should be controlled2MPa below and the biggest value can’t be pass8MPa.5) The connectivity of inner layer and interlayer is bad. The relationship between oil and water is complex. The water energy of this oilfield is abundant and formation pressure decreases slowly. The comparison result between water flooding and natural depletion shows that the effect of injecting water is not well and its recovery is closely to the recovery of natural depletion. Therefore, natural depletion should be adopted.6) The uncertain factors of influencing development effect are analyzed and assessed, which are net size of numerical simulation, the whole volume of rock, permeability, longitudinal connectivity, coefficient of compressibility, irreducible water saturation, the height of oil-water belt zone, skin factor. According to the assessed results we can estimate the influence of those factors to development effect.7) Using established geological model, seven productive strategies are designed. The simulation predict result indicates that the producing effect of increasing volume is better than not increasing volume, interlayer interference phenomenon decreases in some extent when adopting turning on sliding sleeve successively and the time of producing stably is extended. The screened producing strategy is that rate of oil production is about3%in early stage and recovery percent of reserves is up to11.7%after producing18years.8) The numerical simulation result shows that recovery percent of reserves is low. There are three reasons as follows:(1) there are many isolated reservoir, the relationship between oil and water is complex, the degree of producing reserves is low;(2) the distance to boundary water and bottom water is small and water invades quickly.(3) there are many oil-bearing series in the reservoir, but the single pay sand is very thin. Oiliness well section is long. The difference of pressure is big. Fluid channeling and interlayer interference phenomenon are serious.By establishing high-precision3D geological model of Bozhong A Oilfield, including3D geological structure model, certainty and randomness sedimentary model, rock physics model controlled by phased, inaccurate3D geological model, in some certain condition, probable change process is confirmed, then according to the specific purpose, the most reasonable geological model is selected and obtained.On the basis of selected model, numerical simulation research can be carried out, output predict target is updated, formulating the development strategy can be guided and it can provide technical support to optimization and adjustment of development strategy of Bozhong A Oilfield.更多还原