Integration of well and reservoir surveillance techniques—production measurements, reservoir fluid characterization, pressure transient analysis, production logging, relative permeability, and fractional flow—are critical to understanding well and reservoir performance for effective well and field management, particularly in high-cost intervention environments. The complete paper presents a case study in the deepwater Gulf of Mexico (GOM) in which pressure transient analysis (PTA), fractional flow (FF), and production logging tools (PLT) were integrated to identify correctly the cause of, and execute an effective remedy for, a well’s productivity deterioration.
Background
The level of integration achieved in this study is not common practice because most commercial software products do not consider multiphase interpretations in analytical PTA. These limitations leave out the actual effect of relative permeability in the estimated transmissibility values. In this case, integrating fractional flow analysis with a multilayer PTA curve and running a production-logging tool made it possible to separate relative-permeability effects from plugging effects. A coiled-tubing (CT) mud acid-stimulation treatment then enabled recovery of approximately 65% of the well’s lost transmissibility, decreased formation skin from 16 to 9, and instantaneously restored 7,000 STB/D of production.
