Gai J.,International Drilling Company |
Wang D.,International Drilling Company |
Wang L.,International Drilling Company |
Zhang J.,International Drilling Company |
Wang W.,International Drilling Company
Drilling Fluid and Completion Fluid | Year: 2011
Well jida4 is the second ultra-deep exploration well of CNPC in FilGanna block Uzbekistan which is of high-temperature high-pressure high-salt and high-H2S deep low-permeability reservoir. Many troubles such as salt water invasion, salt crystallization, gypsum creep and pipe-sticking occur frequently because of the high pressure salt water formation (combining with gypsum bed) in upper and deep sections. To overcome these difficulties, under-saturated salt water polymer polysulfonate drilling fluid system is put into use from the third section, the density is 2.38-2.43 g/cm 3 and stable at over 160 °C. Owning good inhibitive capability and calcium/salt resistance, the drilling fluid remained stable when high-pressure salt water overflow occurred 5 times and the calsium concentration was 1, 400 mg/L and met the requirements of drilling operation.