New technology extends reach of stepouts

Extended reach drilling (ERD), now commonplace, is used to probe the lateral extent of petroleum reservoirs, reduce drilling costs and safely drill in environmentally sensitive areas. The spatial and geologic control of well bore trajectory through directional surveys and logging-while-drilling (LWD) information allows ERD wells to follow subsurface formations along their lateral extent and more effectively drain petroleum reservoirs. The ERD envelope has been steadily expanding. Ratios of reach to true vertical depth (TVD) of more than 5 have been achieved. The longest stepout, or reach, of ERD wells is in the 25,000-ft range. The popularity and success of ERD is the result of recent advances in drilling technology. Tandem motors, downhole-adjustable stabilizers and performance stabilizers have contributed heavily to ERD progress. New integrated software designed especially for drilling is producing more effective well plans that can be quickly updated. Higher accuracy in directional surveys and increased information from LWD logs help keep actual well bore trajectories closely aligned with planned trajectories. Also, important drilling factors, such as torque, drag, hydraulics and hole cleaning are being better understood. A closer look at some of today`s technology will help explain how ERD operations have reached their present level and will givemore » insight into stepout expectations for the near future.« less