Development of High Temperature Pressure (HTHP) Water Based Drilling Mud Using Synthetic Polymers, and Nanoparticles
Keywords:HTHP, rheology, fluid loss, carbon nanotubes (CNT), sag
It is important to understand the aspects influencing water based mud (WBM) rheology in order to maintain a firm control over rheological properties of high temperature high pressure (HTHP) and high density water based mud. This paper focuses mainly on the rheological properties of water-based drilling fluid under high pressure and high temperature condition. This work focuses on the design, optimization and formulation of a HTHP water-based drilling fluids in accordance with the required specification such as rheological properties and fluid loss. To meet the aforementioned drilling fluid properties, the research was limitless to the use of clay, polymers, and nanoparticles. Polymers provide excellent rheological and fluid loss properties to water base muds but degrade at high temperature. The experimental method used was generally mixing of water base mud with certain formulation and then performing mud testing. The experimentation were conducted according to “Recommended Practice on Standard Field Procedure for Testing Drilling Fluid” API RP 13B and “Recommended Practice 13I Standard Field Procedure for Laboratory Testing Drilling Fluid” API 13I to meet the American Petroleum Institute (API) requirements and obtain trustworthy results. The main laboratory tests involved in this project are mud preparation, static rheology test, pH and HTHP static filter press. A bentonite clay and high temperature synthetic polymers have been successfully tested at 400-degree F with excellent rheological and filtration properties. The base mud formulation consists of the commercial chemicals provided by Scomi Oiltools, Malaysia. The base mud formulation has a stable rheology and excellent fluid loss properties at 400 F. A very thin and impermeable filter cake has been obtained with minimum fluid loss at a temperature of 400 F. Researchers have successfully used nanoparticles for providing excellent rheology, thermal stability and fluid loss control. Two nanoparticles namely, Carbon nanotubes (CNT) and Zinc Oxide were tested on the base WBM system to analyze their effects on HTHP rheology, fluid loss, and filter cake quality. A very positive result has been obtained using Carbon nanotubes (CNT). The use of CNT in WBM increased HTHP rheology by 14% and reduced fluid loss by 25%. Moreover, this research provides solutions to the problems related to HTHP WBM development like clay gelation, solid sagging, and low-end rheology. The aforesaid problems have been fixed by using high temperature polymeric deflocculants, polymeric viscosifier, and bentonite extender respectively.