摘要
To satisfy the requirements of protecting hydrocarbon reservoir of low pressure reservoir horizontal well,by means of research in laboratory,oil-in-water drilling fluid formula with variable density in 0.89~0.99g/cm3 was obtained.This oil-in-water low-density drilling fluid has good capability of emulsion stability,rheological property and anti-sloughing property.The result of application in Daping #1 well showed that the drilling fluid has stable property and can be simply maintained and adjusted for safe and fast drilling operation.It also can satisfy the demands of near-balanced drilling & underbalanced drilling for low pressure horizontal well and geologic requirement.There are obvious effects for hydrocarbon reservoir protection.