生物礁滩岩性气藏含气面积的圈定方法——以元坝气田长兴组气藏为例

Delineation of gas-bearing area of lithologic gas reservoir in organic beach reef:A case study in Changxing Formation,Yuanba Gas Field

开展生物礁滩气藏的储层空间展布特征研究,对于该类型气藏的储量计算和高效开发有着重要意义。由于元坝地区长兴组生物礁滩体埋深超过6 000 m,具有横向变化大和非均质性强的特点,简单的储层预测技术方法难以达到定量研究储层空间展布的要求。在沉积相研究的基础上,开展高精度相控储层定量预测,通过相控储层预测技术的应用,精细刻画了生物礁滩的空间展布特征和边界。评价井成功率达到100%,有效储层厚度20～70 m。目前已探明长兴组气藏含气面积155.33 km2,探明天然气地质储量1 592.53×108 m3。

The delineation of reservoir distribution in organic beach reef is significant for reserve estimation and exploitation.In Yuanba area,the organic beach reef in the Changxing Formation is buried over 6 000 m deep,and is featured by lateral deformation and strong heterogeneity.It is difficult to delineate reservoir distribution quantitatively by simple forecasting method.Based on sedimentary facies,the quantitative forecast of phase-controlled reservoir has been carried out with high accuracy.It describes the distribution feature and limit of organic beach reef.The returned ratio of evaluation wells is 100% and the available reservoir thickness is 20-70 m.The gas-bearing area in the Changxing Formation is 155.33 km2,and the gas-in-place is about 1 592.53×108 m3.