摘要
渤中19-6气田为裂缝性低渗巨厚储层,如何开展井网部署是亟需解决的重要问题。建立了微观渗流模型,模型尺寸为30 cm(高)×80 cm(长)×1 cm(厚);模型基质平均渗透率为0.1 mD,裂缝平均渗透率为2~4 mD;采取注气开发的方式,注气井部署在储层上1/3处,生产井全部射开气层。实验结果表明,裂缝性巨厚储层应充分利用重力辅助驱油机理进行开发。为进一步提高单井产量及气驱开发效果,开展了立体注采井位、井轨迹数值模拟研究、合理注采井距公式推导。结果表明,储层顶部注气、中下部采气的空间立体井网开发效果较好;井方位角及注采井主流线方向与裂缝走向呈45°夹角,可提高单井产量,增大注气波及面积,增强气驱开发效果;根据裂缝分布及公式计算,确定合理井距为1000~1200 m。本文研究在渤中19-6试验区进行了现场应用,单井平均钻遇裂缝密度3.6条/m,开发井实施后初期产能较同类型储层明显提高。
BZ19-6 gas field is a fractured reservoir with low permeability and huge thickness,and how to deploy well pattern in this field is an important problem to be solved urgently.A microscopic seepage model was established with a size of 30 cm(height)×80 cm(length)×1 cm(thickness),an average matrix permeability of 0.1 mD and an average fracture permeability of 2~4 mD.The gas injection method is used to develop the reservoir gas injection wells are deployed in the upper 1/3 of the reservoir,and the whole gas layer is perforated in all production wells.The experimental results show that the mechanism of gravity-assisted oil displacement should be fully utilized to develop fractured reservoirs with huge thickness.In order to further improve single well production and gas displacement efficiency,the numerical simulation of three-dimensional injection-production well location and well trajectory was carried out,and the formula of reasonable injection-production well spacing was deduced.The results show that the spatial three-dimensional well pattern with gas injection at the top of the reservoir and gas recovery in the middle and lower parts of the reservoir has a good development effect.When the well azimuth and the direction of the main stream line of the injection-production well are 45°with the fracture strike,the single well production could be improved,the gas injection swept area could be increased,and the gas displacement efficiency could be enhanced.According to fracture distribution and formula calculation,the reasonable well spacing is determined to be 1000~1200 m.The research in this paper has been applied in the BZ19-6 test area with an average encounter rate of 3.6 fractures per well per meter,and after it is implemented in development wells of the reservoir,their initial productivity is significantly higher than that of the same type of reservoir.
作者
谭先红
范廷恩
范洪军
王帅
牛涛
TAN Xianhong;FAN Tingen;FAN Hongjun;WANG Shuai;NIU Tao(CNOOC Research Institute Ltd., Beijing 100028, China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2021年第3期107-113,共7页
China Offshore Oil and Gas
关键词
裂缝性低渗透巨厚储层
凝析气藏
立体井网气驱开发机理
注采井网部署
井距
fractured reservoir with low permeability and huge thickness
condensate gas reservoir
mechanism of gas flooding development using three-dimensional well pattern
injection-production well pattern deployment
well spacing
