Advanced technology for long term zonal isolation
WellLife® service is a process for improving the safety and the economics of oil and gas wells by applying these technologies:
- Model cement sheath properties that can withstand the stresses from well operations during the well's entire life cycle.
- Develop cement formulations to meet the properties.
- Design placement procedures and deliver the engineered cement system.
- Evaluate and monitor the cement job performance through logs and reservoir performance over the life of the well.
WellLife service models the integrity of the cement sheath and the risk of its failure as it is subjected to different well operations. Based on this we can project the "Delta" economic value or the incremental benefit to the customer by using one cement formulation over the other. This takes into account the cost associated with remedial operations, loss of hydrocarbon due to interzonal communication, non productive time and early water production. Now, the customer can compare the economic value of different solutions and we have the capability to offer them a solution that is cost effective over the life of their well.
WellLife service analyses the effect of well operations on the integrity of cement sheath through an advanced finite element method. The WellLife model is the result of a joint collaboration between Halliburton, Shell and TNO (Building and Construction Research, The Netherlands). The model has been validated through experimental studies and field tests.
The model is backed by development and testing of cement slurries to meet the properties required for long term zonal isolation. Testing of cement specimen in a tri-axial cell under confining pressure is a part of the WellLife service. Material properties such as Young's modulus, friction angle and cohesion of the cement sheath are obtained from this test. Placement of the engineered cement slurry then is designed using Opticem™ and Wellcat™ engineering programs. The material properties of different cement formulations are compiled in a database and are an integral part of the program.