The Performance improvements of a New Drilling Agitator Devicein Jiaoshiba Shale Gas well

Abstract

In order to solve the backing pressure and high friction, a newdrilling agitator device was used in directional and horizontal drilling in Jiaoshiba area of Fuling, Chongqing, China.Due to Jiaoshiba region geological situations are complex, backing pressure and Stick-Slip are always existing in directional drilling, this source of additional torque and drag will lead to low ROP(rates of penetration), poor tool face control, short runs, severe drill string and bit wear, in directional and horizontal applications, this high friction could also lead to high well tortuosity, which will limit the amount of step out and can even impair productivity. The implementation of a unique tool, referred to as a Drilling Agitator Tool (DAT), has demonstrated clear improvement in drilling performance by reducing stick slip and torque at the drill string in Jiaoshiba area. This has enabled reduction in drag and thus improved weight transfer to the bit when drilling through highly interbedded formations, directional applications or long horizontal sections. It has also shown greater accuracy in maintaining tool face control once the static friction was minimized.This paper illustrates case studies from the Jiaoshiba Shale Plays, where the DAT has proven to help reduce torque and Stick-Slip when run on rotary in vertical applications, as well as Motor assemblies through directional and horizontal sections. These improvements in drilling performance have resulted in longer runs and faster ROP compared to offset wells, thus reducing the number of bits and improving the economics in drilling Jiaoshiba shale plays. Selecting high-efficiency PDC bit and screw together with DAT in Jiaoshiba shale gas well can accomplish “one single bit run”.