Sensing at the bit through a modular measurement device

An accurate determination of weight and torque at the bit is essential to maximize drilling performance and to reduce overall cost. With the increase in complexity of wells for oil and gas production, efficient drilling is becoming extremely important. Due to complex wellbore geometry and dynamics resulting from drilling action and formation properties, energy losses have increased tremendously. Such losses and uncertainty in the amount of energy transferred to the drill bit can impair an operator's ability to achieve cost-effectiveness and to optimize performance. The paper describes a memory-based, modular device that can reside inside a drill bit without altering bottomhole assembly (BHA) stiffness and hydraulic requirements. The device can provide accurate measurements closer to the drilling action than other devices on the market. The paper demonstrates the capabilities and the benefits of the tool and shows data obtained through laboratory and field testing. The paper first describes a bit-based modular device, its functionality and its use in capturing acceleration, rotation, weight, and torque at the bit. We also present a case study to show the importance of such parameters in drilling and a validation relative to rig-based data acquisition tools.