A well documented path to improving overall efficiency in project execution is through an integrated team approach which involves both the operator and the service suppliers. This paper describes what can be achieved when such a team adopts a fearless approach to new technology, and dares to think outside existing conventions. To be more specific, the paper covers the engineering, planning, and execution of a HTHP exploration program in the central North Sea by a Norwegian operator.Large areas of the North Sea contain the Cretaceous period of sediments which comprise of a massive hard layer of chalk that historically has posed a major drilling risk and expense to operators in the area. To mitigate expected problems an integrated team was gathered to thoroughly analyze drilling records and lessons learned from previous offset wells and re-engineer the drilling process with the aim of minimizing cost and uncertainty when drilling the most challenging chalk interval.The paper presents the hypothesis that formed the basis for the team effort, and the measures implemented based on said hypothesis. This includes an unconventional bit selection and the use of modern vibration measurement technology and mitigation techniques, as well as a key electro-mechanical modification of the advanced logging and directional suite completed by the lead service provider. The discussion and reasoning behind each step is included and the method was repeated in several wells with the same results, verifying the validity of the findings and making the paper a valuable input for drilling hard chalk.The nominal result from applying the new methodology was a doubling of the rate of penetration (ROP) in the harder layers, and the entire section of problematic strata was drilled in one single bit run. Drilling time was reduced by 12 days when compared to average figures from recent offset wells representing an estimated cost saving of 15 -20% on the overall well budget. The method and savings presented are primarily of interest to stakeholders in the central North Sea, but can also be applicable to other areas with hard chalk and stringers with similar characteristics.

The client had a leaking gas lift valve (GLV), which needed to be replaced to restore the integrity of the well. The side pocket mandrel (SPM), was located at a high angle part of the well, positioned on the low side and sand debris had accumulated in and around the GLV, impairing its retrieval. Tests carried out on surface to attempt to latch a GLV through the sand proved ineffective, even with jarring. To further optimise production, SPMs are being installed at increasing well depths, enabling deeper gas injection into the tubing. Placing SPMs into the high angle section of deviated wells inherently increases the risk of them retaining debris, as was the case in this well. A novel solution, to remove the accumulated sand debris from the SPM was proposed, utilising an orientation sub, run in conjunction with an electric line deployed tractor-suction tool configuration, incorporating a bespoke side facing inlet nozzle. Tests on the designed solution were conducted in the engineering facility, recreating the deviation, orientation and debris expected and evaluating the nozzle alignment and cleanout capability for the expected debris type. These tests proved to be highly successful, giving the customer the confidence to perform the job. The deviation also necessitated electric line tractor deployment of a modified retrieval device. Following a drift and plug setting run, the well tractor and suction tool assembly was deployed and two litres of sand was collected from within the SPM. The subsequent run to pull the faulty GLV was successful, as was the deployment of a replacement GLV. The operation proved this to be an excellent and highly effective example of a rapidly designed and tested, bespoke, electric line deployed SPM cleanout solution.