Natural Flow and Tubing String Design for A Water Drive Reservoir.
Abstract
The design of natural flow and artificial lift tubing strings for the whole life of a water drive reservoir was carried out using data based on synthetic reservoir performance based on a material balance.
The effects of reservoir properties on the life of the well was also investigated. Constraints such as maximum production, maximum drawdown, limitations on surface facilities capacities, as well as available gas lift was imposed.
The production conditions for natural flow, continuous gas lift, and an ESP for later phases of the reservoir was designed and simulated along time by imposing either a constant flow rate or a constant bottom hole flowing pressure.
A forecast of the production of oil and gas as well as the time where tubing strings should be replaced as a function of both the cumulative production and time was presented.
The work was concluded by reservoir pressure was maintained much longer in comparison to other drive mechanism when there is an active water drive preferably edge water drive reservoirs which maintains a steady-flow condition for a long time before water breakthrough into the well.
Introduction
Background of Study
Fluids are stored in the reservoir and must be produced to the surface facilities in order to be measured, treated and finally sold or discarded.
The flow of fluids from the reservoir towards the final processing facility is divided into three phases: Recovery, Lift and Gathering.
Recovery refers to the flow of fluids from the reservoir into the well bore;
Lift refers to the flow of fluids from the bottom of the well bore to the surface wellhead and Gathering refers to the flow of fluids from the wellhead through the gathering network towards the production facility.
Recovery is used in a broader sense a referring to the production including the lift and gathering processes. Lift and gathering process will influence the final recovery of hydrocarbons and must be included in a proper economic analysis.
The flowrate from a well depend on the energy level of the reservoir and the energy losses of the fluids as they flow from the reservoir towards the surface facilities.
In order to increase production flowrates we may use processes or systems to either increase the energy level or to facilitate the flow of hydrocarbons.
Those systems or processes may be used in the reservoir or in the production tubing or gathering system.
The recovery of hydrocarbons may then be classified as: Primary where no process or method is used to increase energy level or facilitate the flow of hydrocarbons inside the reservoir;
Secondary and Tertiary where methods are used to increase energy level and or to facilitate the flow of hydrocarbons in the reservoir.
References
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