基于断层岩泥质质量分数预测的断层侧向封闭性评价

Evaluation on fault lateral sealing ability based on shale mass fraction of fault rock

许新明

Xu Xinming

中海石油（中国）有限公司深圳分公司，广东 广州 510240）

Shenzhen Branch of CNOOC Ltd., Guangzhou 510240, China)

在砂泥岩薄互层段内，断层岩侧向封堵能力取决于的泥质质量分数。在地震资料品质较好的勘探成熟区，可利用速度资料来预测断层岩泥质质量分数，并建立地震速度与钻井岩性的转换模板，进而形成一套基于断层岩泥质质量分数预测评价断层侧向封闭性的新方法。文中以珠江口盆地恩平地区新近系为例，运用该方法建立研究区油气富集带断层侧向封闭性的评价标准，并对该区番禺7翘倾断块构造带断块圈闭进行封闭性评价。研究表明：运用速度谱预测的断层岩泥质质量分数与剪切泥岩涂抹系数具有较好的相关性，能够较真实地反映断层岩充填物的泥质质量分数，可作为断层侧向封闭性评价参数。具有相似构造、沉积成因的勘探成熟区带所建立的岩性￣速度转换模板可用于评价勘探新区断层侧向封闭性，是勘探早期有效评价断层封闭性的方法。

The sealing ability of fault rock in thin interbed of sand and shale is mainly determined by the shale mass fraction of fault rock. Velocity data can be used to predict the shale mass fraction of fault rock if the quality of seismic data is good in the mature exploration area. So a new method used to evaluate the lateral fault sealing ability is introduced based on predicting the shale mass fraction of fault rock, which is obtained from the translation template between seismic velocity and drilling lithology by researching the mature exploration zone. Taking the Neogene layers of Enping Area in Pearl River Mouth Basin as an example, the sealing abilities of the faults developed in Panyu 7 tilted fault block zone are evaluated using this new method, which evaluation criterion is established by hydrocarbon enrichment zone of Enping Area. The results show that there is good correlation between shearing clay smear and the predicting shale mass fraction of fault rock which can represent the shale mass fraction of fault block fillings, so the predicting shale mass fraction of fault rock can be applied to evaluate the lateral sealing ability. The effective evaluation method, which is established using the velocity?鄄lithology translation template in the mature exploration zone with the similar structure and sedimentogenesis, can be used to evaluate the sealing ability of fault during early exploration period.

10.6056/dkyqt201405007