Abstract

Drilling mud is used in drilling operations to ensure well stability and to transport the cut-offs to the surface and is generally classified as; Spud, Lignosulfonate and Polymer types. Spud Mud is the simple mud and mostly used at the beginning of drilling operations. It is mainly composed of bentonite and water. With increasing depth, It is hard to keep well stability and to carry cuttings from the bottom of hole to the surface with the basic drilling fluid. Thus, some materials are used to maintain the rheological and filtration properties of the mud. One of them is vermiculite that is a general name of the hydrated ferromagnesian aluminium silicate group. It has expanded properties when heated. Like all clay minerals, the cation exchange capacity is very high and very similar to the montmorillonites in terms of high cation exchange capacity. In this study, the usage of vermiculite as an additive material in drilling muds was investigated. Spud muds containing vermiculite in different amounts were prepared. Then rheological and filtration analysis of the muds were done according to American Petroleum Institute (API) RP-13B-1 Standard. When evaluated the results, AV reached 41cP, PV 27cP, YP 28lb/100ft2, 10 sec. gel strength 17lb/100ft2, 10 min. gel strength 26 lb/100ft2 and filtration 9cc. The results showed that the vermiculite can might be used as a viscosifier and fluid loss reducing additive material in the drilling mud.