clean out

1. vb. [Well Workover and Intervention]
To remove wellbore-fill material such as sandscale or organic materials, and other debris from the wellbore. Many reservoirs produce some sand or fines that may not be carried to surface in the produced fluid. Accumulations of fill material may eventually increase in concentration within the lower wellbore, possibly restricting production. Cleanouts using coiled tubingsnubbing or hydraulic workover techniques are performed routinely.