Pivot Stabilizer Innovations for Point the Bit Rotary Steerable Systems Result in Improved Drilling Performance for Specific Applications

Abstract

To achieve optimal directional response and maintain superior stability in specific applications, pivot stabilizer design, selection, and evaluation are crucial when used as a near-bit pivot on point the bit rotary steerable systems. This paper describes the progression of stabilizer design through simulations, facility testing, field testing, and in-service performance tracking. Extensive testing and performance evaluation has allowed development of predictable directional response, bit/drill string stability, and other drilling performance metrics of specific stabilizer designs to be rationally chronicled for continual innovation in pivot stabilizer design.Field testing has provided direction for stabilizer characteristics specific to the application. Furthermore, Downhole Drilling Data Recorders (DDDR) have been utilized to monitor and provide a precise record of lateral and torsional vibration. Other measurement tools were required to monitor the directional response of the system. These developments in DDDR technologically have enabled an iterative scientific approach to stabilizer geometric design, yielding in hydraulics optimization and directional response.Stabilizer geometry characteristics are paramount when designing a bottom hole assembly (BHA) for particular formation and operating parameters with identifiable challenges. A fundamental understanding of the impact of pivot stabilizer geometry characteristics is necessary to yield improvements in tool performance and reliability while overcoming these challenges. This knowledge will consequently provide higher drilling efficiency and lower drilling costs.Post run analysis has confirmed unique stabilizer design characteristics are necessary to achieve optimum drilling performance. The design progression chronicled will quantitatively compare the effects of stabilizer design characteristics against field performance. Additionally, the evidence outlined in this document will enhance the industry's understanding of pivot stabilizer's design importance and offer advice for selecting pivot stabilizers on point the bit rotary steerable BHAs.