In line with the time available to introduce a development plan for several fields in eastern Venezuela with low reliability in the production data, it was decided to evaluate the remaining power of the field by a dynamic modeling using a one-dimensional simulator (Peron, SPE-94723-PP). During the model development, the analysis showed inconsistencies in the gas production data. The methodology of correction is analyzed in this paper. Production -primary and secondary- forecasts were performed and employed to approve the field operation plan.
After approving the field development plan under this methodology and due to time constraint while the project was being implemented for sands L, M and N (35% of the remaining reserves of the field) a conventional numeric simulation was performed to increase the reliability of the previous forecasts. The conventional simulation considered the original and the corrected production data from the one-dimensional simulation in order to compare the effects in the historical adjustment.
This paper is intended to show a contrastive analysis of the results in both cases. Also, to evaluate the advantages and disadvantages of the one-dimensional simulation methodology defining the parameters that show uncertainty when it comes to analyze a field (size of the aquifer, formation of the secondary gas cap, relevant production mechanism, dispersion level of phases, trend towards channeling and coning).
The Field is located in the Eastern basin of Venezuela. The operation of the field began in 1938 with the wildcat P1 and up to date a total of 60 wells have been drilled. At present, it produces 2500 of oil barrels daily with an average of 16 active wells (Figure 1).
It has an accumulated production of 26 MMBbls in about 60 productive levels. The total OOIP of the field is 238 MMBbls with a 10.8% of recovery factor.
For maximizing the final recovery factor it was made a static characterization and a numerical simulation of the main sands with the objective of defining the best scheme of operation to drain efficiently the remaining reserves.
The Field is considered mature and is characterized for the presence of many layers with several reservoirs that, in some cases, can be total or partial communicated among them. In addition, the production history is not precise. Errors in the gas production reports and for the first years only cumulative oil and water production are available. These facts cause that the conventional simulation process be time consumer with unpredictable results.
To estimate the remaining potential of mature fields with multiple reservoirs is a task that can consume much time with uncertainty. Like an aid in these cases and based on the commitment to generate a development plan of the field in an established period, a one-dimensional simulation (Peron, SPE-94723-PP) was made for defining the potential of remaining primary and secondary production.
Once the project was approved and within the established time, the results previously obtained were validated with conventional numerical simulations
The objective of this work is to present the application of the one-dimensional simulation and to make a comparative analysis of the results obtained between this and the conventional numerical simulation. Additionally, to present the advantages of using this tool in the validation of parameters that present uncertainty at the time of analyzing a reservoir.