A Holistic Stimulation Approach to Unlock Potential of Horizontal Open Hole Completion in Tight Carbonate: Optimization of Acidizing Treatment and Successful Diversion in Real-Time Using Distributed Temperature Sensing.

Abstract

Abu Roash-D is characterized as a carbonate reservoir in Abu Gharadig field, Western Desert of Egypt. It has a good lateral continuity, contains natural fractures with poor connectivity in addition to formation tightness. To further increase the production from the field, a full development plan for Abu Roash-D carbonate reservoir was initiated with drilling of horizontal wells. The main objectives of drilling such horizontal wells was to develop the tight unconventional reservoirs and increase production by dramatically increasing the contact area with the producing interval, maximizing drainage volume around a well and link the natural fractures network thus, achieving an economically production targets. The effective placement of sufficient acid volume along the open-hole section of such horizontal wells provides significant challenges in acid diversion due to the high permeability streaks that requires a very effective diversion technique for optimal acid distribution a long the open hole lateral for a successful acid stimulation treatment. A fiber optic enabled coiled tubing attempts to tackle some of these limitations. This new approach deploys downhole sensors with fiber optic telemetry inside the coiled tubing string provides a real time temperature, pressure and correlated depth measurments. The fiber optic telemetry allows distributed temperature surveys recording for obtaining temperature profiles across the entire wellbore. Monitoring the distributed temperature sensing (DTS) profiles accompined with downhole pressure data interpretation enables real time diagnostic of downhole events between the stimulation stages providing an important aid to further optimize and improve the performance of stimulation treatments. This paper presents case histories of the first time implementation of horizontal wells in Abu Roash-D tight carbonate reservoir in Egypt's western desert in which fiber optic enabled coiled tubing was utilized to optimize stimulation treatment. The real time monitoring of downhole distributed temperature sensing profiles allowed the identification of both high permeability zones as well as tight zones across the entire openhole lateral. This enabled the operator to take pro-active decision on where to spot diverter or acid, select the best diversion technique and allow for treatment optimization.