Intensification of oil production in long-term developed offshore fields

Abstract

Reasonable allocation of operational facilities in the context of multilayered reservoirs is the foundation of all scientific and practical work on the development of petroleum fields. The parameters of deposits are subject to changes over the course of development, and therefore the previously identified system of objects should be updated periodically. This is especially true for offshore multilayered fields, mining which is time-limited due to corrosion of hydraulic structures and high costs for their renewal. In this regard, the rate of using offshore deposits should be quite high not only at the initial stages, but also remain so in subsequent mining periods. Maintaining a high rate of mining is often associated with high material costs (drilling new wells to compact the well network, applying new methods of enhanced oil recovery, etc.), which is not economically viable for the fields in long-term operation. As the practice of mining multilayered fields in Azerbaijan shows, the enlargement of objects allows compacting a mining network while maintaining the total number of wells for a field. At the same time, average daily oil production rates significantly increase as a result having included capacities of contiguous objects. The research aimed at identifying similarities or differences between adjacent horizons of the section of multilayered deposits. Based on the delineated boundaries, there are possibilities of their joint operation as one object, separate or simultaneous-separate operation of wells under appropriate technical conditions. As a result of such measures, all the wells are used rationally and the development rates are increased without additional capital investment. Section of objects of the 3rd tectonic block of the Neft Daşları offshore field, confined to the Apsheron archipelago of the South Caspian Depression (SCW). The Rodionov’s method was used for a substantial and reliable identification of stratigraphic boundaries. Preliminarily, based on averaged data on 11 parameters, we calculated ꭓ2g:m critical value at 95% significance, corresponding to m=0.05, which is used to assess the state of boundaries between the horizons. Then, by implementing software, the values for the boundaries of adjacent objects were calculated, comparing which with the critical value allowed for a conclusion about possible joint or separate mining of those productive strata. As a result of the implementation of the corresponding program, the clarity of the boundaries between the objects of the 3rd tectonic block of the offshore Neft Dashlari field was determined. The need for joint exploita- tion of horizons VII and VIIa, KS1 and KS2, as well as KaS1 and KaS2 horizons has been determined, which would optimize the mining of the field and is economically feasible.