Drilling fluid technology of deep well , Gangshen18×3

Gangshen18×3 of Dagang oilfield is an important exploration well with vertical depth of 1945. 3 m and slant depth of 2004 m. Located on seashore, it rans through mud-making formations, which requiremud-making prevention and hole stabilization with light drilling fluid (the density is lower than 1. 08 g/ cm3). Above 857 m, light polymer drilling fluid is used and below 857 m, potassium-based polymer drilling fluid with low-density is used to realize quasi-balanced drilling. Results indicate that this drilling fluid system possesses abilities such as hole cleaning, lubricating and sticking preventing and have strong shale inhibition and sloughing prevention. Tests show this well was of high yield of oil.