When drilling an Oil or Gas Well the Bottom hole assembly (BHA) represents a series of components that form the lower part of the drill string, extending from the bit to the drill pipe. During the drilling operation the BHA can become stuck/jammed due to poor cleaning of the...
When drilling an Oil or Gas Well the Bottom hole assembly (BHA) represents a series of components that form the lower part of the drill string, extending from the bit to the drill pipe. During the drilling operation the BHA can become stuck/jammed due to poor cleaning of the hole and subsequent build-up of cuttings. Amongst other major causes of a stuck pipe is differential sticking where the drill pipe is effectively stuck to the wall of the hole by fluid flowing from the hole into the formation. The forces over a long section of drill pipe can be very high and prevent completion of the drilling operation or even retrieval of the drill string. By pumping Lost Circulation Materialâ€™s an attempt is made to clog fractures in the formation that slow or stop this phenomenon.
With directional drilling programmes now exceeding 10km, problems are becoming more common and expensive as oil exploration companies look to access difficult to extract oil reserves from reservoirs which until recently were not commercially viable, particularly in deep water. Methods of disconnecting the BHA need to be activated in highly deviated or horizontal wells where wire-line systems cannot easily be employed. In development and exploration drilling. The costs when the BHA becomes stuck down the hole are considerable.
The aim of the project was to design, develop and ready for market a high temperature variant of a novel intelligent down the hole disconnect tool (I-DISC) which, in the case of a stuck bottom hole assembly (BHA), would provide disconnection from the BHA and extraction in less than a tenth of the time of the existing state of art methods. Integral to the disconnect feature is a circulation valve (I-CIRC) that enhances the products capability to mitigate becoming stuck in the first place.
To conclude the action, whilst the development of Disconnect tool was taken to the detailed design stage, its control system and the circulation valve feature were taken to commercial trial. It is envisaged the control system can now be integrated with the I-DISC and further developed for a host of other drilling tools. The circulation valve is ready for further trials and will be made available as a standalone circulation tool.
Design concepts of the I-Disc technology have been discussed and initial concepts were created using 3D CAD modelling that provide a mechanism for separating the drill string in the event of it becoming stuck. One of the major design considerations is the need to integrate the system with the I-Circ technology owned by Cutting & Wear which is a system being developed to improve hole cleaning and mitigate the circumstances by which drilling assembles become stuck. Several concepts were produced and following initial design reviews one concept was taken forward for FEA analysis where loadings on the system could be analysed and the necessary modifications undertaken. Following FEA analysis a full set of Engineering drawings were produced and final design adjustments undertaken. In addition to mechanical components the technology also requires electronic systems capable of functioning in a high pressure, high temperature and high vibration environment.
A number of precision engineering firms were engaged to manufacture the components which were subject to our standard inspection system prior to assembly of components. The current system is designed to operate at temperatures up-to 150Â°C, during the project period. A solution to 175Â°c is considered a viable however the development of such a system was not taken further than establishing venders for the necessary components.
A dedicated service facility for assembly and disassembly of the tool during development was build and fully utilised during the development phases. This was designed and built in the form of a \'clean room\' due to the high precision engineering involved and the complexity of the components. The facility has proved invaluable for assembly and testing of several prototypes constructed during the course the project. Included in the design of the service facility was all the equipment needed to service the I-Disc tool, the bulk of equipment being the jigs and fixtures needed to assemble and disassemble the tool.
The project was underpinned by a formal governance structure which was put in place on commencement of the project. This was designed to ensure that the project was delivered to the satisfaction of all stakeholders. Apart from ensuring management structures are in place, a risk management plan was produced and reviewed on a regular basis.
A comprehensive plan for dissemination was followed through to ensure potential end-users are aware of the technology. The dissemination strategy that included the building of a website www.intelligentdrillingtools.com that now reflects a broader offer that has evolved during the project time frame. This website provides a comprehensive overview of the technology and the benefits. To further engage with potential users articles were published in trade magazines and participation at several trade exhibitions provided greater awareness of the technology.
The technical innovation within the I-Disc project is the novel mechanical and electronic system DEAP which can be integrated into a modularly configured tool and effectively deployed in down hole gas and oil exploration drilling strings to reduce the risk and costs associated with stuck-in-hole scenarios This technology is adaptable for many other downhole tools. This is a significant technological advancement when compared with current state of the art technology. At its core it uses advanced micro-processor technology combined with logic/system intelligence and will be the only down hole disconnect tool incorporating system intelligence capable of recognising conditions down hole.
The final outcomes of the project are an intelligent circulation tool ICIRC in 81/4â€ diameter size, tested to meet the oil & gas well drilling environment, designs of integrated I-DISC tools at 7â€ diameter & and 8 1/4â€ diameter. Such tools will be capable of operating at temperatures up to 150Â°C. Knowledge of components that may facilitate improved temperature tolerance up to 175ÂºC HT and pressures up to 20,000 psi have also been established. Developed for intelligent disconnects and circulation tools the system can be run in the BHAâ€™s and/or in the heavyweight drill pipe. The technology is capable of use in all oil and gas exploration well (vertical, inclined, horizontal, highly deviated and high temperature high pressure) applications.
The I-DISC tool will provide the ability to reliably and efficiently control the BHA disconnection process with easier â€˜fishingâ€™ for potential recovery of the BHA. Further to this, from an environmental perspective, less use of explosives will be required or less use and potential release of harmful and aggressive chemical cutters into the marine environment would result from this projectâ€™s implementation.
The IDISC and ICIRC tools capability will thus increase the efficiency of oil and gas exploration drilling with reduced energy consumption. A new Business Intelligent Drilling Tools has been created to exploit the outcomes from the project, ultimately this will provide jobs for Managers, engineers, technicians and ancillary workers within the European Union.
More info: http://www.intelligentdrillingtools.com.