海上油田沉积微相精细刻画方法——以珠江口盆地E油田为例

Fine characterizion of sedimentary microfacies in offshore oilfield:Take Oilfield E in Pearl River Mouth Basin as an example

海上油气田因钻井环境限制,基本以平台多分支井开发为主,井型主要为大斜度井、水平井,也有少量直井。因此区域内井网密度小、井距大,储层精细认识难度大。特别在井间、无井区,单砂体刻画及类型划分是难点。以珠江口盆地E油田为例,基于岩心及井震联合波形指示模拟,利用直井垂向确定沉积微相类型、地震属性约束砂体平面发育趋势、波形指示模拟垂向特征确定无井区沉积微相类型及边界、水平井测井横向变化精细界定沉积微相边界等技术手段,结合实际研究区资料,形成了一套海上稀井网多水平井条件下井震结合的沉积微相精细刻画方法,明确了研究区重点层沉积微相类型及其平面分布特征,为后续基于单砂体的精准开发奠定了基础,为科学的地质导向提供了依据。

Limited by drilling environment,offshore oil and gas fields are generally developed by drilling platforms with multilateral wells which mainly include highly deviated wells,horizontal wells and a few vertical wells.Therefore,dense well pattern and large well spacing cause challenge for fine understandings of reservoirs especially for single sandbody characterization and classification in the area of interwells and the area without wells.Take oilfield E in Pearl River Mouth Basin as an example,Based on core and well-seismic tie waveform indicating simulation,using techniques of vertically determining sedimentary microfacies types by vertical wells,constraining areal development trend of sandbodies by seismic attributes,determining sedimentary microfacies types and boundaries in the area with no wells by vertical characteristics of waveform indicating simulation,and finely identifying boundaries of sedimentary microfacies by vertical change of horizontal well logging,and combined with the data of studied area,a set of fine characterizing methods for sedimentary microfacies are established by well-seismic tie under the conditions of sparse well pattern and multi-horizontal wells in offshore oilfields.Sedimentary microfacies types and their areal distribution of the key reservoirs in studied area are clarified.All these achievements lay a foundation for subsequent fine development based on single sandbody and provide evidence for scientific geological guidance.