3D Cement Evaluation in new and old wells using novel X-ray tomography

Evaluation of the presence and integrity of the cement seal between the casing and rock formation in an oil well is crucial for the safe operation of the well. Faulty cementing can even contribute to catastrophic accidents, such as occurred on the Deepwater Horizon rig in the Gulf of Mexico in 2010. Currently available cement evaluation tools are based upon ultrasonic or acoustic technology and provide a valuable source of data for assessing the cement sheath surrounding the casing. This 20 year old technology is sufficient for confirming cement placement and seal for standard, vertical wells. However, it is widely recognized in the industry that such techniques struggle to provide reliable information in modern, complex drilling situations, such as horiz ontal wells or wells using foam cements or low acoustic impedance cements. To address these deficiencies, Visuray is developing a revolutionary three-dimensional cement evaluation tool with full 360 degree coverage based on a novel X-ray tomosynthetic technique. Using high energy X-rays and unique X-ray detectors, this tool will be able to evaluate any cement or sealing material as well as investigate dual casing-cement string wells. With newly-developed data processing and interpretation tools, the user will obtain a high-resolution three-dimensional rendering of the cement distribution around the full circumference of the well. The improvements in technical capabilities and visualization possibilities available with this new tool will give well operator s rapid, reliable information allowing for better-informed decision making in the complex well scenarios commonly encountered today. This new tool will also find wide applicability in the plug and abandonment sector, which is expected to grow significantly in the coming years as more wells age and are abandoned.

The oil industry depends on safe and secure wells to be allowed to operate. The ability to evaluate the well integrity, not only through pressure testing, is a critical measurement for risk reduction. Drilling technology improvement has allowed operators to develop more complex well solutions. The verification of these high technology wells are done by proven but more than 20 year old innovations with short comings. By using novel X-ray based tomography Visuray plan to develop a 3D cement evaluation logg ing tool that can solve for all cement and sealing material including low acoustic impedance solutions like Foam Cement. Based on the same technology Visuray will also develop the first dual "CSG-Cement string" evaluation (CSG-Cem-CSG-Cem-Formation) for t he fast growing Plug and Abandonment segment. The hardware solutions need to be paired with answer products that is conclusive and reliable. Visuray will therefor develop a realistic high resolution image process for fast cement evaluation and decision ma king. Visuray is developing a high energy X-ray platform of tools. The 3D evaluation would mean a ground braking step change in both hardware and software challenges. In short: -Higher downhole output voltage (++450 keV) -New photon emitter design based on Carbo Nano Tubes -New detector solutions -New signal and image solutions -Interpretation and answer products The verification industry is currently using sonic and ultrasonic technologies. A market study indicates that the verification market world wi de by 2015 will be at USD1,2B. A study by Norsk O&G P&A Forum calculated that over the next 20 years operator in Norway spend USD100B. With a 3D Dual Casing verification solution, this could be considerably reduced and possibly as much as 40% through.