油水分布复杂区单一圈闭控藏模式研究

With mainly pure oil blocks of the old oil field have been developed，the remaining recoverable reserves decreased. The syncline area of oil-generating sag and lithologic reservoir area has gradually become the main target area of the old oil fields increasing reserves and production, which have complex oil and water distribution. Therefore, deeply understanding of oil and water distribution and its controlling factors in the complex oil and water distribution area is increasingly important, and it becomes increasingly prominent. But basic research of the application is still relatively weak. The technology of more effective (semi-) quantitative evaluation has not yet been formed. According to weak and significant the link, the types of reservoir, characteristics of oil and water distribution, the basic unit of controlling reservoir and hydrocarbon accumulation mechanism were analyzed, and the constituent elements of the single trap were (semi-) quantitatively evaluated, and the models of a Various types of single trap controlling reservoir were created in the complex oil and water distribution area. Then based on the model of single trap controlling reservoir， quantitative evaluation of the complex oil and water distribution was realized. On this basis, the rich area and the favorable area of oil and gas is selected in the complex oil and water distribution area. This can provide references for exploration and development of oil and gas in the other same regions. And it has important and practical significance to alleviate the current complex situation in exploration and development of oil and gas, and to expand the new area of oil and gas exploration.

随着老油田主体纯油区块的相继开发，剩余可采储量的逐渐减少，油水分布复杂的凹陷向斜区和岩性类油藏区已经逐步成为老油田维储稳产的主要目标区域，深入认识油水分布复杂区块内部油水分布规律及其主控因素的重要性日益凸显。但这方面的应用基础研究还相对薄弱，尚未形成一套较有效的（半）定量评价技术。针对这一薄弱但有重要意义的环节，本项目通过对典型油水分布复杂区已发现的油藏类型、油水分布特征、基本控油单元及聚油机制等分析，着眼于单一圈闭（由单一局部构造与单一成因储层砂体构成）构成要素（半）定量评价，诠释油水分布复杂区块各种类型单一圈闭控藏模式，进而实现基于单一圈闭控藏模式的复杂油水分布（半）定量表征，在此基础上，优选油水分布复杂区油气的富集区和有利区，这可为其他同类型区域的油气勘探与开发提供借鉴与参考，对缓解当前复杂油气勘探与开发形势、扩大新的油气勘探领域具重要实际意义。

随着老油田主体纯油区块的相继开发，剩余可采储量逐渐减少，油水分布复杂的凹陷向斜区和岩性类油藏区已经逐步成为老油田“维储稳产”的主要目标区域，深入认识油水分布复杂区内部油水分布规律及其主控因素的重要性日益凸显，但这方面的应用基础研究还相对薄弱。针对这一薄弱但有重要意义的环节，本项目按计划任务书规定的主要研究内容，选择了松辽盆地南部两井地区扶余油层、乾北地区青山口组和松辽盆地北部三肇凹陷葡萄花油层等油水分布复杂区作为主要靶区，系统研究了油水分布复杂区油气成藏模式、基本控油单元及单一圈闭聚油机制，从本质上诠释油水分布复杂区的油水分布机理，建立各种类型单一圈闭控藏模式，并基于单一圈闭控藏模式实现复杂油水分布的表征。经过3年科研攻关，取得了以下主要成果：（1）建立了基于“单一圈闭”的油水分布复杂区石油聚集新模式，即“单一圈闭聚集，多圈闭（油藏与非油藏）叠置”石油聚集模式。（2）按成藏层次分析法，提出了油水分布复杂区三个层次的成藏规律。即：①区域成藏规律，具有“主元控油，多元耦合富集”特征；②三级构造成藏规律，具有“三级构造控势，单一圈闭控藏”特征；③单一圈闭成藏规律，具有“局部构造控界，单一砂体控层”特征。（3）形成了一套单一圈闭构成要素（单砂体和局部构造）精细描述技术，提出了“分流河道控制的平面多支、垂向多层的河控带状砂体空间叠置关系是引起储层复杂多变的直接原因”新观点；建立了5大类局部构造-单砂体组合模式，并划分出3大类26亚类单一圈闭。（4）建立了不同类型单一圈闭（或油藏）内油水分布模式，确定了局部构造、单砂体及二者组合关系是控制不同类型单一圈闭（或油藏）内油水分布特征的主控因素。（5）创新提出了油水分布复杂区油水分布机理，即不同类型的单一圈闭是油水分布复杂区的最基本、最小控油单元，平面多支、垂向多层的单砂体和复杂的局部构造及二者之间组合形成的圈闭（或油藏）以及非圈闭（或油藏）在空间上复杂叠置是造成油水分布极其复杂的根本原因。该项研究成果不仅可以丰富和完善现代石油地质理论，同时可为其他同类型区域的油气勘探与开发提供借鉴与参考，对缓解当前复杂的油气勘探与开发形势、扩大新的油气勘探领域具有重要的实际意义。