The presentation “OPEN-HOLE WIRELINE CONVEYANCE RISK MANAGEMENT (NEW MODELS, TECHNOLOGIES & INSIGHTS)” will be given by Guy Wheater from Gaia Earth Group.


In this talk, Guy will address the fundamentals of wireline conveyance risk management, and share new models, technologies and insights that have enabled successful wireline operations on some of the world’s most challenging wells.

The subject of wireline conveyance has gained more attention in the last decade or so, due to more aggressive well profiles, increased tool string complexities (e.g. 9000 lbs sampling strings) and ongoing reservoir depletion. Clients are seeking a detailed engineering process for risk reduction and sticking mitigation, to ensure high operating efficiency and the best data quality. It will be shown that on challenging wells, conveyance management may be the #1 factor for formation evaluation success. Forensic analysis of > 100 global cable sticking events suggest that ~ 95% of fishing jobs may be predictable and avoidable at the well design stage.

The main aspects of wireline conveyance risk will be addressed, including wireline descent risks, tool & cable sticking risks, depth control risks and swabbing. It will be shown that fluid mechanics may have a wide ranging impact during job execution and should be assessed at the job planning stage. Selecting conveyance aids for specific runs and environments will be emphasized.

The talk will digress into the genesis of cable protection (tension modelling, hardware and geophysical frameworks) and how sticking risk can be benchmarked – with some quick case studies.

The deployment of a digital wireline standoff (~ 70 runs to date ) has revealed great insights into cable & tool dynamics down-hole, leading to the development of a down-hole depth tool for reservoir validation. It will be shown that there are regimes where “depth control” (as we know it) may be invalid, leading to survey inefficiencies and poor data quality.

Guy strongly advocates a change in paradigm from “log this” to “lets collaborate”. A set of recommendations will suggest that early engagement, teamwork and technology integration can deliver safe and efficient wireline operations in wells that would have been considered too challenging just a few years’ ago.


Guy Wheater has enjoyed >30 years in the energy sector so far. After a solid grounding in oil and gas research (Shell then Schlumberger) he moved into field operations for Schlumberger Oilfield Services (Wireline & Testing), completing a series of operations and management assignments in the North Sea, Middle East, and Africa. He joined Gaia in 2004 as a QA/QC specialist, contributing to a wide range of projects from Trinidad to Viet Nam (supervising six logging providers in both wireline and M/LWD services). He designed and developed Gaia’s Cable Protection System (GCPS) after recognizing that cable sticking had been a persistent problem since the late 1950s. GCPS is now used by 25 clients worldwide and the pre-job modelling is considered mandatory by many well engineering departments. Guy continues to push forward in conveyance research, building devices and sensors that illuminate “down-hole physics” whilst improving operational performance. Creative output includes four SPE papers and more than 10 patents for numerous down-hole tools. He holds a Ph.D. in mechanical engineering (turbulent combustion) from the University of Cambridge in England. He lives by a simple mantra: “see more, do more, fix more”.