Evaluation of Rheologi cal Prope rties of Or ganoclay as Water -base Drilling Fluid in Iran

Bentonite is a cla y mineral p roduced in many place s around th e world. It has a significant numb er of applications such as preparation of green sand moulds for metal ca sting as a binder, as a th ixotropic fluid in wall and road con struction an d as an additive in drilling fluids fo r oil-well, geothermal and water-well drilling to control viscosity and filtration pro perties [۱]. Water bento nite suspensions have strong colloidal properties and increase liquid vis cosity, beha ve as non-Newtonian fluids when sheared whil e under certain circumstances have the unique a bility to gel when not sh eared. The concentration of bentonite in water suspensions varies depending on the applicatio n, for example, may ra nge between ۳ and ۷% in drillin g fluids [۲, ۳] to control rheological and filtr ation properties. In the past year s there has been significant research to study the rheological behavi or of benton ite suspensions [۴-۶]currently there is a good understanding, however, full und erstanding o f the mech anism of v iscosity and gel gener ation whenbentonite is a dded in water is still u nder question. After the necessary p eriod of hy dration of bentonite particles, rheology of ben tonite suspensions depends among other things on bentonite concentration, the presence of ions, particularly electrolytes, temperature and p H of the sus pension [۱].

کلیدواژه ها:

Nano Organoclay ، Rheologic al ، Cation E xchange Ca pacity (CEC) ، Drilling Fluid