摘要
针对泌阳凹陷下二门地区地表起伏大,泥质白云岩发育,速度横向变化快,地震反射层位与钻井层位深度误差大,构造高点与控制圈闭的小断层难以落实等难点问题,在成像处理中采取以下方法技术,利用微测井约束层析反演提高近地表速度建模精度;采用高密度小步长沿层百分比扫描、井速度趋势约束提高均方根速度场精度;采用速度场低频趋势约束与地震解释层位约束的方法进行层析反演,构建深度域初始层速度模型。结合射线密度分析、低降速带及高速层的速度分析,将微测井约束层析反演得到的近地表速度模型与中深层速度模型进行融合建模。为了消除各向异性引起的深度误差,利用各向同性速度场以及深度误差生成多属性数据库,对比分析深度域地震解释层位与钻井层位深度吻合性,不断更新各向异性速度、δ与ε模型,直到各向异性成像横向不出现构造异常点,纵向井震层位深度误差小于10 m为止。依据各向异性速度场进行各向异性叠前深度偏移处理,提高了井震匹配关系以及地震资料信噪比、保真性和断裂成像精度。通过对各向异性叠前深度偏移数据体进行解释,发现了一批断块圈闭,在圈闭高点部署的B437井、B443井、B449井获高产油流。
The Xia ermen area of the Biyang Sag features a large surface undulation,well-developed argillaceous dolomite,and rapidly changing lateral speed.The depth error between the seismic reflection and drilling horizons is large,and it is difficult to identify the structural highs and small faults controlling the trap.In the imaging process,micrologging-constrained tomography inversion was used to improve the precision of near-surface velocity modeling.The root mean square velocity field accuracy was improved using high-density small steps along the horizon percentage scans and log velocity trend constraints.A tomographic inversion constrained by the low-frequency trend of the velocity field and interpreted horizons was performed to construct an initial horizon velocity model in the depth domain.Based on ray density and velocity analyses of the low-and high-velocity layers,near-surface velocity models obtained from micrologging-constrained tomographic inversion were combined with mid-depth velocity models.To eliminate depth errors caused by anisotropy,a multiattribute database was generated using an isotropic velocity field and depth errors.The depth-domain interpreted seismic horizons were compared and matched with the depth of the drilling horizon,and the isotropic velocity,δ,andεmodels were continuously updated until there were no tectonic anomalies in the lateral direction of the anisotropic imaging,and the error in the depth of the vertical well seismic formation was less than 10 m.Anisotropic pre-stack depth offset processing based on anisotropic velocity field improved the log-seismic matching relationship,signal-to-noise ratio,fidelity,and fracture imaging accuracy of the seismic data.By interpreting the anisotropic pre-stack depth offset data,several fracture block traps were identified,and highly productive oil flows were obtained from wells B437,B443,and B449 deployed at the high points of the traps.
作者
赵军才
张永华
徐照营
杨兴圣
赵伟
ZHAO Juncai;ZHANG Yonghua;XU Zhaoying;YANG Xingsheng;ZHAO Wei(Sinopec Geophysical Corporation Huabei Branch,Zhengzhou 450000;Exploration and Development Institute of Henan Oilfield Company,Sinopec,Zhengzhou 450000)
出处
《石油物探》
CSCD
北大核心
2022年第6期1006-1015,共10页
Geophysical Prospecting For Petroleum
基金
中国石化科技部项目(ZDP17012)资助。
关键词
泌阳凹陷
井约束
层析反演
各向异性速度场
叠前深度偏移
Biyang Sag
well constraints
tomographic inversion
anisotropic velocity field
pre-stack depth migration
