深圳大学学报（理工版）2026，Vol.43Issue(5)：557-566,10.DOI:10.3724/SP.J.1249.2026.05557
定容气藏排气降压地层的能量评估及井筒模拟方法
Energy evaluation and wellbore simulation of gas-venting in constant-volume gas reservoirs
摘要
Abstract
During deep and ultra-deep drilling,the coexistence of multiple pressure systems results in an extremely narrow safe drilling-fluid density window.For abnormally high-pressure gas zones,controlled-pressure gas-venting operations lack a quantitative basis for formation energy assessment and venting parameter optimization.For the pressure depletion process of constant-volume gas reservoirs,this study innovatively establishes a method for dynamic formation energy assessment,reservoir key-parameter inversion,and wellbore multiphase-flow simulation covering the entire process of"pump-off underbalanced gas influx-circulating overbalanced gas-venting",and integrates these local components to form a full-chain quantitative framework linking"formation evaluation-parameter inversion-wellbore prediction-operation optimization".Based on the material balance method and the Beattie-Bridgeman real-gas equation of state,models are developed to predict the original gas reserves,gas storage volume,and evolution of formation conditions.A reservoir permeability inversion method is proposed by combining a gas-influx deliverability function with field pressure and gas-venting data.Furthermore,a full-process two-phase transient flow model covering the entire gas influx-venting is established and solved using the finite volume method to predict the peak gas flow rate and peak casing pressure under different formation-fluid release volumes.The proposed method is validated using field data from Well DY1H2-2.After a cumulative gas-venting volume of 1.58×10⁴ m³,the predicted formation pressure drop is 10.8 MPa,compared with the measured value of 8.2 MPa.Ten gas-venting simulations show that the average prediction errors of peak gas flow rate and peak casing pressure are both below 15.00%.Under a representative operating condition,the predicted peak gas flow rate is 3 258 m3/h,compared with the measured value of 3 300 m3/h,while the predicted peak casing pressure is 3.5 MPa,compared with the measured value of 3.8 MPa.The results show that the proposed method can effectively characterize the formation pressure decline and wellbore gas-venting responses during pressure depletion in constant-volume gas reservoirs,providing a quantitative basis for optimizing the operating schedule of controlled-pressure gas-venting and supporting well-control safety decision-making.关键词
油气井工程/控压钻井/井控安全决策/精细控压排气/地层能量评估/气液两相瞬态流动/有限体积法Key words
oil and gas well engineering/managed pressure drilling/well-control safety decision-making/precision-controlled-pressure gas-venting/formation energy assessment/gas-liquid two-phase transient flow/finite volume method分类
能源科技引用本文复制引用
徐先觉,左星,陈泽,刘庆,舒腾飞,唐贵,李赛,李红涛..定容气藏排气降压地层的能量评估及井筒模拟方法[J].深圳大学学报（理工版）,2026,43(5):557-566,10.基金项目
National Key R&D Program of China(2023YFB3210205,2019YFA0708303) （2023YFB3210205,2019YFA0708303）
National Natural Science Foundation of China(51904264) （51904264）
CNPC Science and Technology Project(2024ZG35) 国家重点研发计划资助项目(2023YFB3210205,2019YFA0708303) （2024ZG35）
国家自然科学基金资助项目(51904264) （51904264）
中国石油天然气集团有限公司科技资助项目(2024ZG35) （2024ZG35）
