Rationale for choosing wells for well intervention of mature production fields

The presentday development stage of West Siberia oilfields is characterized by the primary production of highly productive reservoirs and the increasing of oil resources in non-uniform and the reservoirs of low permeability. To achieve oil recoverability factor, according to the plan, one needs to reconstruct or develop the waterflooding pattern.
The method of well selection for well interventions, that is described in the article, is intended for the regulation of oil recovery in oilfields of advanced stages of development by means of the front displacement of the water injection; construction of complemental row of injection wells; the sources of water injection; the separation of layers of the individual development.
At the time the dispersed pattern-type injection and the line drive flooding turns into the selective floodiing system. Producing fields - the Samotlorskoe and the Novo-Pokurskoe within the Vartovskiy structural high - were chosen as the exploration targets.
The principle of well selection for well interventions is based upon the determination of the interaction degree between bordering wells; the interaction degree is estimated by calculating the coherence function; oil and gas production and injection data are usually transferred from the time domain to the frequency domain beforehand.
Materials and methods
The solution of the problem is based on the statistical analysis of the fluid dynamics of oil production and water injection according to monthly operating reports, 2D allocation maps of geological parameters.
Carrying out of the frequency analysis of oil production and water injection by means of the ECM became a new method of testing.
Results
The method of determination of the well interference between production and injection wells allows to estimate the efficiency of the reservoir pressure maintenance system and to correct water flooding patterns, if necessary.
Сonclusions
1. The evaluation analysis of the well interference and the value calculation of the squared absolute value of the coherency allows to estimate the conformance.
2. Reservoir compartments, not covered by the displacement of the existing system of water injection were identified, according to the results of the frequency analysisof Novo-Pokurskoe oil field. The maps with notations of well interference were used while planning changes during well operations and well intervention.
3. Recommendations, concerning with geological and technical well interventions in Novo-Pokurskoe oilfield allow to increase oil production in areas of low reserve recovery.