摘要
大北气田大多数井岩心测井显示物性很差。选取大北202井区邻井钻井平台的泥浆,选用大北102井和大北202井2口井的油层岩样,在实验室摸拟地层温度和围压下,研究钻井过程中钻井液在不同温度、压力、浸泡时间、渗透率下的工作液侵入深度和污染深度。试验表明,岩样没有明显的泥饼形成,泥浆滤失量大,对储层损害严重,损害深度较深。随着泥浆滤液在岩心内滞留的时间越长,它与储层岩石作用就越强烈,伤害也越严重;压差和温度的增大也会加重地层损害的程度。对岩心进行水锁伤害评价试验,储层水锁指数大于50%,表明该地区存在中等偏强水锁,水锁伤害较严重。
The well logging showed that the core properties of most wells in Dabei Gas-field were poor,its permeability was generally lower than 0.1×10-3μm2,some of it was less than 0.01×10-3μm2.In order to study the formation damage degree of low permeability and tight sandstone,experimental simulation was performed on the working fluid's invasion depth on the cores from Wells 102 and 202 and pollution depth under the condition of formation temperature and confinement pressure in different temperatures,pressures,shear rates,soak times and permeabilities of drilling fluid.The drill fluid damage experiment result of the rock samples from Wells Dabei102 and Dabei 202 indicates that there are no apparent mud cakes formed in rock samples,the its filtration loss is large with serious formation damage.With the increasing of detention time of filtrate in core,the reaction between reservoir rock and filtrate was more and more intensely,the formation damage was more severe.In addition,the increase of pressure drop and temperature would aggravate the damage too.Therefore water-lock damage evaluation test is performed on the cores of Dabei Gas Field.The water-lock index of Dabei Well 102 and Dabei Well 202 is more than 50%,it indicates that the water-lock in the area is medium to high and the water-lock damage is relatively serious.
出处
《石油天然气学报》
CAS
CSCD
2012年第7期146-148,152,共4页
Journal of Oil and Gas Technology
基金
国家科技重大专项(2011ZX05015)
关键词
低渗透气藏
致密砂岩
损害程度
大北气田
low permeability Gas-field
consolidate sandstone
damage evaluation
Dabei Gas-field
