oa Reservoir surveillance and logging applications for brownfield optimization

As more of our fields come to the later stages of their life, there is a drive to optimize production. To do that reservoir management and surveillance is crucial for the understanding of the reservoirs. Due to difficulties in completing surveillance programs and logistical constraints, limited surveillance has resulted in large uncertainties. The past decade has seen tremendous growth in the number of high-angle and horizontal wells while the declining production from mature fields has presented us with complex well-production issues. New production logging technology is now helping to provide a better understanding of fluid movement and enabling high confidence in decisions leading to successful interventions. Production logging in high-angle wells that produce a mixture of fluid phases is challenging because of the associated complex flow that radically changes the physics and technology of the measurement. Depending on the borehole deviation, the velocity and fluid holdup of different phases can change dramatically for a given flow rate. We present field examples that show the value of regular surveillance and some of the methods that can be used in obtaining good results. We will demonstrate the added-value of comprehensive flow diagnosis and the positive implications for various surveillance objectives during brownfield optimization. The benefits are two-fold: successful well interventions in the short term, and valuable information for reservoir management in the medium to longer term.