应力敏感油藏压裂井产量动态规律研究

The Research on Stress Sensitive Reservoir Fracture Well Production Dynamic Rule

基于广义达西定律及流固耦合理论建立了渗透率各向异性疏松砂岩脱砂压裂人工裂缝—油藏系统流固耦合模型,模拟分析了压裂造缝及降压生产流固耦合作用对储层应力、孔渗特性及生产动态的影响.研究表明:脱砂压裂造缝对储层物性影响主要体现在近井眼10m以内,且造缝宽度越大影响越显著,远离井眼及人工裂缝后,储层物性变化明显放缓;开井初期,储层孔渗参数变化显著,随生产时间增加,储层孔渗参数趋于稳定,仅随空间位置而变化;在压裂造缝及降压生产流固耦合作用综合影响下,近裂缝储层弹性模量显著增加,储层孔渗参数显著降低,压裂井产量明显低于常规渗流模型预测结果.对应力敏感性较强储层进行生产动态分析时,必须充分考虑流固耦合作用影响.

Based on the generalized Darcy＇s law and fluid-solid coupling theory, this paper constructed sand out fracturing artificial fracture and reservoir system fluid-solid coupling model which was in permeability anisotropy unconsolidated sand formation; and simulated also analyzed influence of fracturing creature and depressurized production fluid-solid coupling effect on formation stress, porosity permeability characteristics and production behavior. Sand out fracture creation influence on formation physical property was mainly showing within 10 meters of borehole ; and the bigger the creation width, the more apparently of influence ; the farer from borehole and artificial fracture, the slower of the formation physical property changing Formation porosity permeability parameters were changing outstanding at the beginning of well production; formation porosity permeability parameters which were only changing with space location were getting steadily following the increasing of the production time. Near fracture formation elasticity modulus was apparently increasing under the combination influence of the fracture creation and depressurization production coupling effect; and formation parameters was apparently decreasing; and the fracture well production was lower than normal seepage flow model prediction result. The fluid-solid coupling effect influence must be taken into consideration when the formation with stronger stress sensitivity is being done the production behavior analysis.