Cost overruns can very easily create excessive unbudgeted costs during well construction due to various unplanned issues including lost returns, differential sticking, and narrow pore pressure/fracture gradients. To better plan for potential  events, operators  budget an additional cost into there authorization for Expenditure (AFE) to cover the unexpected, this can significantly impact drilling budgets. Technical and operational risks versus the potential return on investment (ROI) are critical factors in determining whether a project proceeds. 

In many cases the best drilling practices used to address trouble zones are limited to a few conventional methods with a narrow range of effectiveness. Also, a lack of rock mechanics knowledge can prevent the most efficient solution being applied.

Some operators are implementing planning programs that assess and integrate the latest processes and technologies to address these risks up-front.  Systems such as managed pressure drilling, drilling with casing / drilling with liners, and solid expandable casing have been successful in mitigating these cost overruns. Applying the latest tools and techniques can efficiently address operational risks and trouble zones to ultimately reduce NPT and associated costs.

Employing common practices and technologies that are typically ineffective and that drive up NPT cost should be considered unacceptable. Common sense well construction used with validated conventional and new technologies have proven their worth by reducing expenditures and risks, preventing the loss of wells, and increasing the operator’s ROI.

The presentation will cover the tools and systems used to evaluate and assist in overcoming these potential hazards.