摘要
鄂尔多斯盆地神木气田上古生界二叠系多层段含气,但主力含气层段为太原组、山西组和石盒子组盒8段^([1-2])。单井钻遇有效储层个数平均为9个,有效储层厚度平均为36.1 m,平均孔隙度为6.4%,渗透率为0.38 mD,属典型的多层段含气低孔、低渗致密岩性气藏。针对多层段致密储层开发难点,长庆气田不断探索、实践,形成了适合神木气田的有利目标区评价方法——综合指数法。首先在充分选取与单层产能有关的众多地质参数,并逐一拟合分析其权重大小的基础上,得到单层产能指数计算公式,建立单层有利目标区评价标准;其次依据产气剖面测试明确不同层段的产能贡献权重,结合单层评价结果,求取叠合层产能综合指数;最后结合经济评价,确定综合指数的经济开发界限,优选开发有利目标区。该方法不仅指导了神木气田的高效、规模开发,而且对其他类似气藏的有效开发具有一定的借鉴意义。
There are multiple gas-bearing layers in the Permian of Shenmu gasfield, Ordos Basin. The main ones include Taiyuan Formation, Shanxi Formation, and Shihezi 8 Member. After some drilling, it is found that there are nine effective reservoirs in average, and their average thickness of 36.1 m, average porosity and permeability of 6.4% and 0.38 mD, respectively. This gasfield belongs to a typical tight lithological gas reservoir with multiple gas-bearing layers, and low porosity and permeability. To solve some difficulties in its development, a comprehensive index method to evaluate favorable target areas available for this gasfield was developed. At first,more geological parameters relative to single-layer productivity are thoroughly selected to implement a match one by one, and to further analyze their weight, gain a calculation formula of singerlayer productivity index, and develop an evaluation standard for singer-layer favorable target areas. Secondly, based on gas-producing profile test, the contribution weight of productivity in different layers can be made clear, and integrated with the evaluation result on single layer, the multiple-layer productivity index may be calculate. Finally, combined to economic evaluation, the economic development boundary of comprehensive index can be determined, and the favorable target areas can be optimized. This method not only guides a high-effective and scale development for Shenmu gasfield but also gives a reference for similar gas reservoirs.
出处
《天然气勘探与开发》
2016年第4期23-25,39,共4页
Natural Gas Exploration and Development
基金
中国石油重大专项"低/特低渗透油藏有效开发技术研究-长庆油田油气当量上产5000万吨关键技术研究"(编号:2011E-1306)
关键词
神木气田
多层段含气
产能指数
权重系数
经济极限产量
有利目标区
Shenmu gasfield
multiple gas-bearing layers
productivity index
weight coefficient
economic limit production
favorable target area
