沿着水平井钻井液侵入对储层污染评价  

Evaluation on Pollution of the Reservoir Caused by Drilling Fluid Invasion Along the Horizontal Well

作　　者：左美玲[1] 郭立辉[2] 何金宝[3] 张强[4] 崔志松[4] 兰雪[5] 

机构地区：[1]东北石油大学,黑龙江大庆163318 [2]中国石油新疆油田公司实验检测研究院,新疆克拉玛依834000 [3]辽河油田钻采工艺研究院,辽宁盘锦124010 [4]中国石油新疆油田公司勘探开发研究院,新疆克拉玛依834000 [5]吉林油田勘探开发研究院,吉林松原138000

出　　处：《当代化工》2015年第8期1851-1854,共4页Contemporary Chemical Industry

摘　　要：钻井液侵入会对油层造成不同程度的污染,一方面使油层孔隙堵塞,另一方面钻井液侵入后由于流体的饱和度发生变化后导致相对渗透率下降,都将导致油井产量降低。因此,必须对水平井井筒周围的污染区进行污染评价。运用有限元数值模拟方法计算两相渗流中沿水平井钻井液的侵入深度,将污染区含水饱和度和相对渗透率曲线相结合,计算出污染区平均渗透率及表皮系数。通过单因素分析的方法研究钻井液侵入对水平井近井筒油层的污染程度与泥浆粘度、正压差的关系。泥浆粘度和污染程度关系的研究表明,四个泥浆粘度方案中,随着泥浆粘度的增加,污染程度变弱。方案一较方案二的表皮系数高50.7%,方案二较方案三高48.2%,方案三较方案四高36.5%。正压差和污染程度关系的研究表明,随着正压差的增加,污染程度变强。正压差1、3 MPa对应的表皮系数分别为0.039、2.003,正压差3 MPa较正压差1 MPa表皮系数增加显著。Drilling fluid invasion will cause different degrees of pollution to the reservoir. On the one hand, it makes the reservoir pore jam;on the other hand, the relative permeability decreases due to the fluid saturation change after drilling fluid invasion, which all will lead to oil production reducing. Therefore, it＇s very necessary to carry out the pollution evaluation around the horizontal well area. In this paper, drilling fluid invasion depth of two-phase flow along the horizontal well was calculated by using finite element numerical simulation method. Combined with water saturation in polluted area and relative permeability curve, average permeability and skin factor of the polluted area were calculated. The relationship between wellbore reservoir pollution level and different mud viscosity, positive pressure during drilling fluid invasion was studied by the method of single factor analysis. The research on relationship between mud viscosity and pollution degree shows that, in four mud viscosity schemes, with the increase of mud viscosity, the pollution degree decreases. The skin factor of No. 1 scheme is higher than that of No.2 scheme by 50.7%, the skin factor of No.2 scheme is higher than that of No.3 scheme by 48.2%, and the skin factor of No.3 scheme is higher than that of No.4 scheme by 36.5%. The research on relationship between positive pressure and pollution degree shows that, with the increase of positive pressure difference, the pollution degree increases. The skin factors of 1 MPa pressure difference and 3 MPa pressure difference are 0.039 and 2.003, the skin factor of 3 MPa pressure difference is significantly higher than that of 1 MPa pressure difference.

关 键 词：水平井 钻井液侵入 污染区平均渗透率 泥饼 

分 类 号：TE357[石油与天然气工程—油气田开发工程]