One of the critical challenges that operator companies must deal with in the development of unconventional reservoirs, is to define a strategy that diminishes the impact of the frac hits and the EUR degradation by the phenomenon of the parent child effect. The problem appears when new wells (child wells) are drilled and fractured close to those that have already been in production (parent wells). Due to the pressure depletion, the new wells are not as productive as the original ones. The alternatives to deal with this problem are diverse. There is more than one technical-economic option to deal with this effect, as it has been documented in the US unconventional developments.
This paper describes the techniques tested by one of the operator companies in an oil window Vaca Muerta field. The methods employed consisted of pressurizing the parent well with water and redesigning the completion of one of the child wells. The production interferences observed along the fractures in the horizontal wells were measured with water-oil tracers.
There are comments about the imbibition effect and the results are compared with analogous fields in a similar Vaca Muerta oil window where these types of strategies have not been executed. The results observed after this operator implemented jobs are basically avoiding damaging productivity on the parent well and preventing a high level of EUR degradation on the child wells.
This paper shows that the methods tested by the operator can increase the Vaca Muerta fields asset value by preventing EUR degradation. In terms of hydrocarbon volumes to be recovered during a factory development mode, the impact of implementing such described techniques can be very high, because many horizontal wells will be involved on this situation.
Vaca Muerta Formation is located in the middle west of Argentina. According to Barredo & Stinco, (Unconventional Reservoir Geology of the Neuquen Basin – SPE-170905-MS), the Vaca Muerta Formation is the most important source rock in Argentina.
