Journal of Materials Science and Engineering with Advanced TechnologyAuthor's: RENALLE CRISTINA ALVES DE MEDEIROS NASCIMENTO, LUCIANA VIANA AMORIM, DANIEL SILVEIRA LIRA and JULIANO MAGALHÃES
Pages: [71] - [95]
Received Date: Received December 2, 2011
Submitted by:
The differential sticking is a phenomenon that occurs when the drill pipe becomes stuck, without rotation, impeding it to move up and down inside the well, but with the drilling fluid flowing normally. The properties of the cake, the differential pressure, the deficiency in the well cleaning, and an unstable well are some of the factors responsible for the pipe sticking. Several studies affirm that the formulation of the fluid has direct influence on the risk of differential sticking incidents. Thus, the present work aims to evaluate the influence of thermal aging on the differential sticking coefficient of clay, and water drilling fluids with polymer and lubricant additives. To this end, 14 formulations of clay and water fluids were studied, varying the polymer type, and the type and amount of lubricant. The rheological properties (apparent viscosity (AV); plastic viscosity (PV); and gel strength (GS)) were determined by using a Fann 35A viscometer. The filtration properties (fluid loss (FL) and cake thickness (CT)) in a Fann filter press and extensometer, the lubricity coefficient (LC) in an EP-lubricity tester from Ofite, and the differential sticking coefficient (DSC) in a differential sticking tester from FANN. In general, the results showed that the addition of lubricants to the clay, and water fluids with polymer additives constitutes one of the main factors for the thermal resistance, improvement of the lubricity coefficient, and reduction of the risk of differential sticking of the fluids.
differential sticking, drilling fluids, lubricity, thermal aging.
