塔里木轮古7井区钻井液的评价与改进研究

The evaluation of alkali-sensitivity and parameter optimizing of aqueou clay based drilling fluid of the seventh wellblock in Talimu

塔里木轮古7井区油储量丰富,但产量低,储层损害严重。由于钻井液的滤液侵入地层会引起泥页岩水化膨胀,发生水锁等现象,导致井壁不稳定和各种井下复杂情况,因此有必要对应用于该井区的钻井液进行分析。通过对塔里木轮古7井区TIII油组的原用钻井液参数的评价分析及该储层碱敏性的实验研究,得出用于该井区的钻井液对地层损害严重的原因主要为pH值过高和滤失量过大。通过对降滤失剂的筛选,得出该井区钻井液应采用"基浆+2%FLOCAT+3%LOCK SEAL"作为优选钻井液。

The oil reserves of the Tarim Lungu seven well area are rich,but the production is low,the reservior is also seriously damaged.As the invading of the mud filtrate will cause the mud shale formation to occur hydration expansion,and the phenomenon such as water lock which lead to the shaftlining become unstable and occur various underground complex situation,so it is necessary for the corresponding analysis to the drilling fluid of this well area.By the analysing of parameter of aqueous clay based drilling fluid and the evaluation of alkali-sensitivity of the TIII oily layer group of seventh wellblock,Talimu,there are several effect factors generating the great formation damage by using the drilling fluid,that is related to higher pH value and bigger filtration.By the filtering fluidlossagent,the drilling fluid used in the field must be＂mud fluid＋2%FL0CAT＋3%LOCK SEAL＂.