石油および環境バイオテクノロジージャーナル

概要

Analyzing in situ Geothermal EnergyContribution to Hydrocarbon Reservoir Pressure

Olafuyi Olaleken and Ekeregbe MP

In any closed fluid system there exists a relationship between pressure and temperature. For liquid system, a change in density with a change in temperature impacts on the fluid pressure if the fluid expansion is contained in a rigid system boundary. Geothermal energy in the earth interior has been exploited for different purposes such as heating and power generation. But no influence of geothermal energy on hydrocarbon reservoir fluid in situ in the earth interior has ever been thought of. This pressure contribution to reservoir pressure due to geothermal energy is what this paper seeks to quantify by examining the thermal conductivity of the reservoir fluids- formation system and the reservoir architecture. Because of the complex representation of the different components of the reservoir, the relationship between the pressure and temperature in the reservoir has a complex polynomial relation which depends on changing reservoir parameters. The pressure contributed due to geothermal energy is significant depending on reservoir architecture, fluid and formation properties. A major limiting factor is the reservoir pay zone thickness known as the traverse length. This paper presents a relationship between temperature and pressure in the reservoir and allocates pressure contribution to temperature effect in the reservoir by assuming that the hydrocarbon reservoir is in effect in contact with a geothermal reservoir. Relationship between temperature and pressure in the reservoir was formulated and pressure contribution was allocated to temperature effect in the reservoir by assuming that the hydrocarbon reservoir is in effect in contact with a geothermal reservoir. The results show that there exist a polynomial relationship between pressure and temperature in the reservoir. The higher the reservoir pressure the lower the in situ oil density and ultimately lower geothermal pressure contribution. The geothermal pressure contribution in reservoir pressure decreases as the traverse length (pay zone thickness) increases, its effect is negligible above 40 feet pay zone thickness. There exists polynomial relationship of degree six (6) between pay zone thickness and geothermal pressure contribution