Affiliation:
1. Halliburton
2. Petroleum Development Oman
Abstract
Abstract
Oil field development have recently been connected with lateral drilling that enables higher exposition of reservoir formation and enhanced production. Lateral drilling brought new challenges of energy transfer especially when drilling with surface driven bottom hole assembly. Having a downhole, and at the bit measurement of the ratios of weight transfer is important to enhance drilling parameters and reduce lost energy and lost times in this drilling section.
Directional drilling recently has been mainly done with rotary steerable systems that are driven from the surface top drive with rotations and weight. In lateral drilling and due to the nature of the wellbore geometry, the energy from the surface is not transmitted to the drill bit due to high frictions between the drill string and the open-hole, cased hole, and the formation, along with the hole cleaning limitation due to the inclination at which the drilling is happening. Rotation, Weight, and Torque are a main limiter of the drilling rate of penetration of the section. Having in bit sensors enabled recording for the full length of the section to record bit motions and evaluate the rotation energy ratio transition, the strain sensor installed inside the bit enabled the calculation of the exact energy at the bit from both the weight and the torque.
Measuring at bit the weight, rotation, and torque at a high frequency rate enabled continuous sampling to help establishing an energy transfer ratio between the surface and real energy at the bit to enable the cutters to fail the rock and drill a certain rate of penetration. This information opened new limits to the lateral application drilling with several possible modifications in the inputted levels of energy in the system while measuring dysfunctions to reduce risks of damage to the downhole drilling assembly especially that this change in energy input was coupled with a change in downhole vibrations and system energy losses. Mechanical specific energy ratios along with dysfunction study at the bit helped building a new drilling road map, where with the same bottom hole assembly and drill bit reduced the lateral section drilling time by 22% compared to the previous average.
The new digitally enhanced drilling road map along with downhole measurements of energy at the bit have changed the drilling approach in the studied lateral section application to enable better energy transfer to the bit along with lower bit and drilling assembly vibrations to create more consistent performance with lower rates of failure and enhanced well construction time reducing the total cost and risk.