Techbits: Wellbore Collision Avoidance and Interceptions - State of the Art

Abstract

Techbits This article highlights key knowledge that was shared at the SPE’s “Collision Avoidance and Well Interceptions Applied Technology Workshop” held in Inverness, United Kingdom, in September. It raised awareness of issues concerning wellbore collisions and interceptions. Planning to ensure that well collisions do not occur during drilling is a complex and demanding task that is often not given the high priority that it requires in drilling programs. Assumptions are made of the validity and accuracy of historical data that is unfounded. Conversely, planning well interceptions when required in operations such as relief wells/drainage intercept wells requires a sound working knowledge of wellbore-positioning technologies and techniques. Wellbore interceptions and proximity placement are becoming critical applications for the development of some reservoirs, specifically tar sands and coalbed methane. Wellbore collision avoidance is entering the daily skills requirement of drilling engineers as they plan more infill wells and more cluster (pad) drilling. Ultimately, demonstrating the knowledge of the borehole position during the drilling process is becoming a regulatory requirement that demands greater understanding by the drilling engineering community and drilling/asset managers. Are drilling engineers trained, competent, and adhering to procedures designed to manage the intricacies of wellbore surveying requirements as applied to collision avoidance and well interceptions? The workshop covered the topic under the headings: Survey-database integrity Collision-avoidance management Practical directional drilling Relief-well design Interception techniques The workshop emphasized that wellbore collisions must be treated as high-risk events that must be managed by systematic survey-management procedures. Borehole-position errors are a critical input to subsurface modeling and have a major effect on field economics. Several workshop committee members are also members of the SPE Wellbore Positioning Technical Section (SPE WPTS) that has published two SPE papers on the ellipse of uncertainty error models commonly referred to as the Industry Steering Committee on Wellbore Survey Accuracy (ISCWSA) models. Summary of the Workshop Workshop attendees shared and learned about current good practices of the complete management cycle of well-positioning activities. Planning, policies, data management, practical application, and technology were all addressed. This was accomplished during presentations, discussions, and breakout sessions with industry experts. Some in-depth presentations and insightful results were produced, including good practice in designing a survey program requirements for survey-database management managing anticollision risk practical insights into relief-well planning and drilling