Most of the industry operators and service companies have developed and implemented a directional drilling collision avoidance rules based on strict controls to prevent well collisions and subsequent human and environmental damage. These rules are formulated based on best practices and mitigation procedures across the industry experience. However, these rules are sometimes found to be severely restricted to the optimal wellbore positioning of wells representing mainly the safe drilling to prevent surface or deep collision risks with offset wells.
Historically ADMA-OPCO and ZADCO were adapting the basic collision avoidance rules from its shareholders policy and mainly depends on service companies' internal policy to rely on execution phase which was creating huge well spacing among drilled wells resulting in extreme narrow path for future well placement which was affecting field development severely.
The need for a comprehensive collision avoidance practice and policy was eminent when the world- class ERD project with artificial Islands as drill centers was commenced in 2013, which instigated the process for developing a Wellbore positioning and collision avoidance policy for ADNOC offshore concessions operated by ADMA and ZADCO.
In general the collision avoidance procedure should define on how to maximize the safety by avoiding or managing the collision with critical offset wells during the planning and execution phases of the drilling program. The scope of this document includes, but is not limited to, a set of anti-collision policies including standards, practices and guidelines to manage the master database structure and integrity, position uncertainty, surface location, survey program, collision avoidance procedure, wellbore survey operation, quality assurance, data integration and communication protocols to the interested parties, etc.
Developed policies helped the drilling team to standardize the technical and operational consistency for safe planning, supervision and execution of directional drilling operation activities greatly. Outlining the roles and responsibilities of the well collision avoidance and wellbore positioning procedures eased the operation greatly in an offshore Artificial Island drill center environment with 100s of ERD wells being planned to be drilled.
The brief technical details of verity survey technologies and surveys management advancements are covered in the guidelines to get an general education on subject matter to the end user which will help them to identify and finalize the survey program to drill the well safely. The detailed collision risk matrix and risk mitigation procedure guidelines has helped the drilling engineers to conduct the required risk assessment and mitigation plans in place during planning phase itself and supervise it during execution with enough control measures in place. The roles and responsibilities of each service companies involved is categorically mentioned in the policy allowing all parties to implement their contribution without failure.