摘要
考虑钻开储层时粘土水化膨胀、微粒沉积与释放、微粒运移堵塞等对井壁周围储层渗透率的影响 ,建立了一套与钻井液完井液有关的储层损害程度数学模型 ,包括 :渗透率与孔隙度联立方程 ;连续性方程 ;微粒运移方程 ;粘土水化膨胀速率方程 ;侵入液微粒沉积速率方程 ;岩石微粒释放速率方程 ;微粒运移喉道堵塞模式。运用有限差分近似方法求解模型参数和测量可测参数 ,并将此过程编成计算机程序 ,可计算出钻开储层时钻井液对储层的损害程度。室内模拟试验表明 ,建立的模型是有效的。
A series of mathematical models predicting the degree of formation impairment related to drilling fluid are established,in which the known dominant damage mechanisms including clay swelling,fines depositing and fines migrating to plug the throat pores have been considered.These models are:the simultaneous equations about permeability and porosity,a equation of continuity,a equation of fines migration,a equation of swelling rate for clay hydration,a equation of fines depositing rate in the borehole wall,a equation of fines releasing rate;model of plugging throat by fines migration.The degree of formation damage,the damage permeability and the damage skin factor induced from drilling fluid when a reservoir has been penetrated can be calculated,by solving the model parameters from an implicit finite difference solution and by measuring the measurable parameters.This process has been programmed.The simulating test in a laboratory demonstrates the efficiency of the models.
出处
《钻采工艺》
CAS
2002年第5期80-83,共4页
Drilling & Production Technology
关键词
储集层特征
预测
钻井完井液
油气层损害
数学模型
drilling fluid,reservoir damage,reservoir characteristics,mathematical model
