Abstract
We present a comprehensive wellbore cleanup toolbox, which combines and optimizes the benefits of jetting, milling and chemical dissolution techniques. The system will clear obstructions from the wellbore and clean back to the tubing wall in a safe non damaging manner.
Conventional cleanup techniques use wash tools, which are inefficient, solvent bullheading which is poorly targeted and wastes reagents or milling tools which can be damaging to the wellbore. These present a less than optimized solution to a commenly occurring problem.
We have developed a tool box which includes an optimized jetting tool for cleaning out soft and weakly consolidated materials. It also presents benefits when used with solvents, or chemical reagents by delivering the fluids directly into the blocking or plugging obstructions with sufficient energy to accelerate the dissolution process and minimize the fluid consumption.
For insoluble materials with a clearance hole we use a self powered jetting tool with the non damaging, Sterling Beads, abrasive system. This will remove scale or other obstructions from the well without damage to the wellbore or jewelry.
For hard and insoluble bridges or plugged wellbores we use a hybrid jetting and milling system. Using a modified PDM with a radial jetting head and small PDC mill. The mill is sized to be smaller than the tool so it cannot contact the tubing or jewelry. Hence the system is safe and non damaging. In addition by using a smaller mill the drilling torque is reduced and the system is more reliable than an equivalent conventional system.
