高有机质丰度泥岩压实的计算误区及定量校正方法

Misunderstandings of high organic matter abundance mudstone compaction and quantitative correction methods

柳波¹ 贾梦成 2 李天翔³ 金亮¹ 王浩力¹

东北石油大学非常规油气成藏与开发省部共建国家重点实验室培育基地，黑龙江 大庆 163318 中国石油大庆油田有限责任公司第四采油厂，黑龙江 大庆 163511 黑龙江省地震局，黑龙江 哈尔滨 150090

State Key Laboratory Cultivation Base Jointly?鄄constructed by Heilongjiang Province and the Ministry of Science and Technology for Accumulation and Development of Unconventional Oil and Gas, Northeast Petroleum University, Daqing 163318, China No.4 Oil Production Plant, Daqing Oilfield Company Ltd., PetroChina, Daqing 163511, China Heilongjiang Earthquake Administration, Harbin 150090, China

文中以古龙凹陷青一段富有机质泥岩为例，应用平衡深度法对研究区目的层的孔隙流体压力分布进行了预测，重新认识了青一段异常压力分布规律，并探讨了源内泥岩油与超压的关系。结果表明：古龙凹陷青山口组压实曲线经过校正后，比正常压实趋势线斜率减小30.0%~42.0%；青一段由于有机碳质量分数较高，其欠压实的幅度降低最为明显，可达26.7%~40.0%。估算出的超压最大为6~8 MPa，反映该地区以前可能过高地估计了古龙凹陷青一段超压的幅度。因此，在前人研究的基础上，提出了消除有机碳对声波时差影响的方法。该方法能准确预测出地层压力，对其他地区富有机质泥岩压实趋势研究具有借鉴意义。

In this paper, taking the rich organic mudstone in the Member 1 of Qingshankou Formation of Gulong Depression as an example, used the equilibrium depth method, the pore fluid pressure distribution of the target layer in the study area was forecasted, the distribution law of abnormal pressure in the Member 1 of Qingshankou Formation is reanalyzed and the relationship between the shale oil in the source rock and overpressure is discussed. The results suggest that the slope of the normal compaction curve is reduced by about 30.0%￣42.0% after the compaction curve of Qingshankou Formation in the Gulong Depression is corrected. Because of the high content of organic matter in the Member 1 of Qingshankou Formation, the decrease of the undercompacted amplitude curve is the most obvious, which can reach 26.7%￣40.0%. The maximum of overpressure after correction is about 6￣8 MPa, reflecting the extent to which previous studies in the region may overestimate the overpressure to the Member 1 of Qingshankou Formation of Gulong Depression. Therefore, on the basis of previous studies, this paper proposes a method to eliminate the influence of organic matter on the acoustic time difference, which can accurately predict the formation pressure, and is useful for the study of the compaction trend of rich organic matter mudstone in other areas.

10.6056/dkyqt201801006