DRILLING FLUID TECHNOLOGY FOR DIRECTIONAL WELL WITH LONG OPEN HOLE

This paper describes the drilling fluid systems and maintenance programs for medium inclined directional well with long open hole, and it focuses on drilling fluid lubricity and anti-sticking property, hole cleaning capability and wellbore stability control. Drilling fluid performance in four wells are evaluated. The drilling fluid technology has been successfully used in a directional well with total measurement depth (TMD) of 3625m, hole deviation of 49°, horizontal displacement of 1229m, and 3224.5m open hole, in which 2292m is in the inclined section.