珠江口盆地潜山储层地质力学及压裂参数优化研究

珠江口盆地珠一坳陷惠州27-1井区作为潜山油气储层，压裂层段厚度大、层数多、非均质性强、压裂改造难度大，对于人工裂缝的在潜山储层中的拓展延伸规律认识困难。针对此问题，首先建立动态参数测井解释模型，并与静态岩石力学数据协同校正，建立一维岩石力学剖面；结合深部成岩理论，建立三维地质力学模型，真实模拟研究区块成岩环境；最后基于三维地质力学模型，研究排量、液量、砂比、前置液占比、射孔层位厚度等参数对裂缝纵向和平面延伸规律的影响，优化压裂设计。结果表明，惠州27-1区块，杨氏模量平均值为45.47GPa，最大水平主应力平均值为100.91MPa，最小水平主应力平均值为80.98MPa，泊松比平均值为0.30。排量6-7(m3·min-1)、液量600-700m3、砂比10-15%、前置液比例50%-60%、射孔厚度8-11m为最优施工参数，为现场施工提供指导意见。

Geomechanics and fracturing parameter optimization of buried hill reservoir in Pearl River Mouth Basin

As a buried-hill oil and gas reservoir in Zhuyi Hollow of Pearl River Mouth Basin, Huizhou 27-1 well area has large thickness of fractured interval, multiple layers, strong heterogeneity, and great difficulty in fracturing reconstruction. Therefore, it is difficult to understand the expansion and extension law of artificial fractures in buried-hill reservoir. In order to solve this problem, the dynamic parameter logging interpretation model is first established, and the static rock mechanics data are co-corrected to establish a one-dimensional rock mechanics profile. Combined with the deep diagenesis theory, a three-dimensional geomechanical model is established to simulate the diagenetic environment of the block. Finally, based on the three-dimensional geomechanical model, the influences of parameters such as displacement, fluid volume, sand ratio, pre-fluid ratio and perforation zone thickness on the longitudinal and plane extension of fractures were studied to optimize the fracture design. The results show that the mean value of Young''s modulus is 45.47GPa, the mean value of maximum horizontal principal stress is 100.91MPa, the mean value of minimum horizontal principal stress is 80.98MPa, and the mean value of Poisson''s ratio is 0.30 in Huizhou 27-1 block. The optimal construction parameters are 6-7m3/min displacement, 600-700m3 fluid volume, 10-15% sand ratio, 50%-60% Pad fluid ratio and 8-11m perforation thickness, which provide guidance for on-site construction.