Reliable Technology for Drilling Operations in a High-Pressure/High-Temperature Environment

Abstract

Abstract The development of oil and gas assets is becoming more complex with reserves being found in more challenging environments. Wells are being drilled to greater depths and in areas where the temperature gradient is higher leading to the requirement for downhole equipment to withstand temperatures in excess of 302°F (150°C) and pressures in excess of 30,000 psi. Directional wells require measurement while drilling (MWD) and drilling systems that operate reliably in the challenging environments. The problem of high pressure is solved using seals to isolate the inner equipment from the wellbore fluid, protecting it from variations in material properties and geometrical dimensions. The greater challenge to electronic components is in the high-temperature environment. Conventional electronic components are generally rated to 158°F, 185°F and 257°F (70°C, 85°C and 125°C), respectively, which is far below the rating required to build a high-temperature MWD and rotary steerable system (RSS). New techniques were required in the design of MWD and RSS tools for high-temperature wells. The paper describes the development of high-temperature drilling equipment that can be used in environments up to 350°F (175°C) and at pressures of 30,000 psi. The authors utilize case histories to demonstrate how the system provides a performance change in the challenging environment.