Wellbore Positioning
Do you know where your wellbore is?
The question is not rhetorical, but one the SPE Wellbore Positioning Technical Section (WPTS) strives to ensure that well operators can answer with high accuracy. The ability to do so is central to safe drilling operations, optimum production, and maximum recovery of reserves. And knowing the answer depends on good wellbore survey management, a practice that frequently is deficient among drilling operations managers. It is a problem that the WPTS is trying to remedy.
Obtained by means of gyroscopic systems or magnetic systems such as measurement-while-drilling (MWD) and logging-while-drilling (LWD) tools, a wellbore survey provides essential depth and directional data as a well is drilled. The use of data from properly designed surveys enables operators to ensure that a well will have a safe pathway to its target and avoid a collision with another wellbore. Survey information is also crucial in preparing to drill a relief well, should it be necessary.
In addition, surveys provide geoscience staff and government regulators with important data, play a significant role in forensic investigations, and aid in estimating reserves. Operators also sometimes obtain post-drilling surveys to achieve an enhanced accuracy of wellbore locational data.
Safety and Economic Benefits
Because the highest priority is to drill wells safely, conducting a wellbore survey is first and foremost a safety practice. However, the WPTS believes that many people in the industry fail to recognize the full economic benefit that good survey practice adds to drilling projects by reducing the uncertainty of achieving the intended well path. Thus, they underestimate the economic cost of inadequate survey practice.
The growth of pad drilling, in which multiple wells are drilled from the same location and spaced closer together, accentuates the need for good wellbore survey practice for safety and economic reasons.
“If you don’t know where your well is, how do you know what your reserves are?” asked Robert Wylie, product line director of Dynamic Drilling Solutions at National Oilwell Varco.
Reflecting this theme, Wylie moderated a WPTS topical luncheon titled “Why Did Your Reservoir Just Move?” at the 2014 SPE Annual Technical Conference and Exhibition (ATCE). Good survey management drives increased value for wells, reservoirs, and companies, he said.
