Technical difficulties and specific measures of cementing in the Bachu-Maigaiti Area

Since the complicated geological conditions in Bachu-Maigaiti Block, where low-pressure thief layers, abnormal high-pressure formation, long section salt beds and high-pressure brine formations were wildly distributed, and easily led to poor cementing quality. In view of technical difficulties of cementing in this area, excellent performance plugging isolation fluid system, ultra-low density slurry system with density of 1.20~1.45 g/cm3, and 2.60~3.00 g/cm3 ultra-high density salt tolerant slurry system were researched. leak protection technology of low-pressure thief layer cementing, ultra-high density cementing technology of ultra-high pressure zone, and special cementing technology of salt beds and high-pressure brine formations were improved and optimized, which formed series of technical measures and achieved good effects. The field application results in Well Mabei1 and Well PSB1 show that difficult cementing problems of low-pressure thief layers, abnormal high pressure layers and ultra-high pressure salt-water formation were solved effectively, and exploration well cementing quality were improved in Bachu-Maigaiti area.