Zodiac Aerospace (United Kingdom)

Abstract Stuck pipe remains as one of the major risks in the drilling operation that could cause significant non-productive time (NPT). The earlier stuck pipe risk is predicted and mitigated, the higher the chance of preventing its occurrence in the first place. In this study, a new model was proposed using random forest (RF) algorithm together with sliding window technique to quickly detect the symptoms of potential stuck pipe, by capturing the hidden pattern and trends of certain real-time drilling parameters (hook load, Torque, standpipe pressure and weight on bit) fall outside of the boundaries calculated dynamically from the Pauta Criterion. After being trialed on wells for both offshore and unconventional, the developed model is able to give the early indication of an impending stuck pipe from 3 minutes to 43 minutes ahead of its actual occurrence, thus leave the rig crew valuable time window to take proper interventions.

Quantitative trading in oil-based markets is investigated over 2003–2010, with a focus on WTI, Brent, heating oil and gas oil. A total of 861 spreads are considered. A novel optimal statistical arbitrage trading model is applied, with generalised stepwise procedures controlling for data snooping bias. Aggregating upward and downward mean-reversion, profitable strategies are identified with Sharpe ratios greater than 2 in many instances. For the top categories, average daily returns range from 0.07 to 0.55%, with trade lengths of 9–55 days. A collapse in the number of profitable trading strategies is seen in 2008. Robustness to varying transactions costs is examined.

Production of a formal safety case is a valuable part of the safety management of a safety related system. A safety case is a written justification that the given system will be tolerably safe during installation, commissioning and operation, and in some cases decommissioning. A well-written safety case will give all stakeholders (operating authority, members of staff and regulators) justifiable confidence that the system is safe to operate and to continue in operation. Although production of a safety case is now regarded as best practice in many quarters, there is still relatively little experience of writing safety cases and only a limited amount of literature on the topic. Many safety engineers find it a daunting task and some safety cases are still poorly structured, difficult to understand and less than compelling.