断层古侧向封闭能力恢复方法及其应用

A recovering method for ancient lateral sealing ability of fault and its application

在泥岩断层泥比率RSG算法定量评价断层现今侧向封闭性理论模型的基础上,利用最大断距相减法恢复断层古断距,并计算断层古RSG,以此建立一套断层古侧向封闭能力恢复方法;以南堡凹陷3号构造为例,对断裂古侧向封闭能力进行定量评价。研究结果表明:利用南堡3-2断层圈闭油藏数据所建立的断层古侧向封闭能力评价函数预测得到的南堡3-3断层圈闭古侧油水界面为-3.225 km,断层古侧向封闭能力弱是造成该断层圈闭油气钻探失利的主要原因;断层古侧向封闭能力同样影响着断层圈闭的有效性,是油气勘探决策中需要考虑的一个重要地质因素。

On the basis of the theoretical model that uses SGR algorithm quantificationally to evaluate present lateral sealing ability of faults, fault ancient SGR value was computed to establish, a recovering method of ancient fault lateral sealing ability by using the maximum fault throw subtractive method recovered ancient fault throw. Taking fault trap in Nanpu 3 structure as an example, fault ancient lateral sealing ability was recovered using the established method. The results show that by using the function formula of ancient fault lateral sealing ability established by data of reservoir in NP3-2 fault trap, ancient oil-water contact（OWC） of NP3-3 fault trap is predicted as -3.225 km. The basic reason of the failed fault traps drilling is that the fault ancient lateral sealing ability is weak. Fault ancient lateral sealing ability is also an important geologic factor to be considered in decision-making for hydrocarbon exploration, which affects the fault trap efficiency.