A Risk Analysis Approach Using Stress Analysis Models to Design for Cement Sheath Integrity in a Multilateral Well

Technical risk analysis was used during the planning phase<br>of a critical cement job on a North Sea operator’s platform to<br>ensure complete zonal isolation across the production zones.<br>The well was a multilateral with two legs, with heavy<br>emphasis on the quality of interzonal isolation. The critical<br>risk in this cement job was that the well would become<br>uneconomical if either main-bore or lateral isolation failed.<br>This well was chosen as a first-time application for a new<br>stress-modeling and risk-analysis methodology using a<br>complementary suite of software tools. The cement job<br>optimization included analysis of all critical parameters to<br>achieve optimum mud removal and mitigate the risk of cement<br>sheath integrity failure.