低密度高强度水泥浆在板深7井中的应用

Application of lightweight cement in well Banshen-7

针对板深7井工程地质情况,固井时采用耐高温低密度水泥浆体系。实验结果表明,耐高温低密度水泥浆体系密度低(1.57 g/cm^3),强度高,稠化时间易于调节,并具有低失水量、低污染、抗高温、防窜和防漏等性能,利于保护产能,满足了深井固井各项指标的要求。声幅测井结果表明,全井优质。

Well Banshen-7 is a wildcat well located in Banqiao area, its total depth is 5191. 96 m, and the BHCT and BHST are 145 C and 180 C respectively. Un-derbalanced drilling technology is employed for formation protection; thus it is necessary to use high temperature-resistant and low-density cement slurry for cementing. Suitable cement slurry is selected based on lab tests and the formulation is presented. The light cement slurry, which has a density as low as 1. 57 g/cm3, shows high compressive strength and adjustable thickening time, and it exhibits low fluid loss, minimal contamination and high temperature tolerance; gas migration and lost circulation is effectively prevented. Field test in this well is successful, and cement bond log shows an excellent cementing.