How Halliburton OMV Petrom increase production with StimTube™ wellbore

Overview 

OMV Petrom in Romania had a number of aging wells with declining production. Perforations had become clogged. In many such cases, the Marathon StimTube™ tool would be ideal to open them up. When activated, it produces gas that forces surrounding liquid into perforations, expanding the perfs into reservoir rock. However, when working with the tool, accurate and thorough prejob modeling is important to help ensure safety and results. Halliburton worked with OMV Petrom for months to model various sizes of charges against conditions in the well, rock properties, fluid volume and more. This modeling determined how to get the best results with the least risk. It paid off. The crew completed the job without any safety incidents and with improved production. OMV Petrom reported a sustained production increase of 66 percent from the well.

Challenge:  

OMV Petrom in Romania had a mature field with declining pressure and clogged perfs that reduced production. They hoped that the Marathon StimTube tool could help open the perfs and boost production. Normally, to be considered as a candidate for the StimTube tool, a reservoir should have a bottomhole pressure of approximately 3,000 psi. This back pressure partially shields the formation and casing from the propellant while funneling the force into perforations. Because the pressure in OMV Petrom’s mature field was low, predicting tool behavior became a challenge. Very little data was available on reservoirs with low bottomhole pressures. 

Solution: 

Specialists from both companies worked together to understand how to help prevent safety issues and help ensure good results. They modeled the effect of several different sizes of propellant after accounting for numerous wellbore properties, such as diameter; formation pressure, porosity and rock strength; casing strength, gauge, composition and age; the location of perforations; well depth; and perforation locations. Models showed that StimTube stimulation could succeed with acceptable risk if the right-sized charge was placed perfectly. Being placed even slightly above or below the perforations would greatly diminish the effect of the stimulation. Crews must place the tool adjacent to perfs for maximum effectiveness.

Result: 

After six months of planning and collaboration, a Halliburton crew set out from the Netherlands and drove across Europe to Romania. Upon arrival at the job site, the Halliburton crew discovered yet another issue: a language barrier. However, with the help of translators, both crews worked well together. Everything went as planned. The job finished without a safety incident. 66 percent sustained production increase after two months.

 After withdrawing the tools and water from the well, the OMV Petrom crew restarted the pumps and found an immediate increase in production. Two months later, when production had stabilized, OMV Petrom found that sustained production had increased by 66 percent. They attribute the success of the job to exceptional planning that kept people and assets safe. OMV Petrom and Halliburton are currently looking at performing similar operations on additional wells and are in the process of qualifying wells