南海某油井地应力剖面的测井构建研究

THE STUDY OF IN-SITU STRESS SECTION CONSTRUCTION OF AN OIL WELL IN THE SOUTH CH INA SEA BASING ON LOGGING DATA

地应力计算分析是井壁稳定性评价、油气井出砂预测、套管损坏变形分析、射孔设计优化以及压裂施工设计的前提与基础。海上油气井的垂向应力,由海水压力、未测井段岩层压力以及已测井段岩层压力三部分引起。在分析密度随深度变化趋势的基础上,确定了未测井段岩层压力;依据压裂曲线,利用破裂压力孔隙弹性计算模型,计算得到了在两个水平主应力方向的弹性应变量;并基于地应力的组合弹性经验关系模型,利用测井数据计算并构建了南海某油井的地应力剖面,为该井开发过程的出砂预测、套管损坏变形分析以及射孔设计优化等提供了依据。

To calculate in-situ stress is the base of the evaluation of sidewall statility of borehole, the forecast of sand production, the casing damage and distortion, the perforation desigh optimization and the design of hydraulic fracturing. To the offshore oil and gas well, the vertical stress is the result of the pressure of seawater, the pressure of formation without logging data and the pressure of formation with logging data. The pressure of formation without logging data has been calculated through the analysis of density along with the depth change trend. Basing on fractureing calculation model with pore elasticity theory, the elastic strain in horizontal direction has been determined with hydraulic fractureing curve. Basing on elasticity combination empirical model of in-situ stress, the in-situ stress section on the oil well in the South China Sea has been calculated with logging data. The result provided useful basic data for the forecast of sand production, the casing damage and distortion, the perforation design optimization and the design of hydraulic fracturing.