Eric Pierre De Rouffignac

Acoustic Stimulation to Mitigate Near-Wellbore Damage

Near-wellbore formation damage reduces productivity in oil and gas wells. Formation damage can be caused by fluid invasion during the drilling and completion process and by particles in the production stream. The conventional technique to remove this damage is fluid injection to dissolve the damage. A promising new technique to remove the near-wellbore damage is high-frequency acoustic stimulation. A specially designed acoustic tool is deployed on wireline or coiled tubing (CT) to selectively treat damaged reservoir intervals.

Near Wellbore Stimulation by Acoustic Waves

Reduced well productivity or injectivity is often caused by near-wellbore formation damage due to the interaction of reservoir formation with drilling and completion fluids. The problem can be further compounded by production induced formation damage. A prime example is fines migration and fines plugging of rock pores or gravel packs. High frequency sonic waves, especially ultrasonic waves have been used in many industrial applications to remove contaminants like dirt, oil, and grease from parts immersed in fluids. An obvious extension of this application is the removal of wellbore impairment by exposing it to high frequency acoustic waves. Although the concept is old, successful largescale application of acoustic well stimulation is not common. Greater understanding of the technology’s applicability and limitations are essential in order to design effective downhole acoustic tool and guide successful field implementation. To this end, we have embarked on a dedicated project to mature the technology, which includes dedicated experimentation and tool design. In this paper, we focus on some key experimental results and discuss potential applications in production engineering.