Advance reservoir petroleum engineering - Essay Example

The test use both pressure drawdown and build-up tests (Gringaten, 2012). A successful test for a well ensures that a step change in rate is created. This is achieved by: closing a flowing well or injection well also referred to as build-up or falloff: by opening a well that was previously shut in (drawndown): or injecting in a previously closed well (injection). The rate change creates a pressure change in the same well during exploration or production testing but if in a different well it is called interference testing.

In case of layered reservoirs, the change in rate in each individual layer is determined by production logging tool. The pan system is the software used to calculate reservoir properties. At the initial stage, a simple model for the reservoir is defined which is made more complicated when different reservoir properties are found. The best option is the simplest reservoir model that assumes a radial flow in a homogeneous, isotropic reservoir and single phase fluid at the initial stage of building the model.

Calculations are simplified by adding two assumptions; outer boundary reservoir taken as the infinite acting and the constant flow rate at the well bore also referred to as the inner boundary. The report defines pressure drawdown testing and the system of determining different reservoir properties in each step. The equation (a) gives the bottom hole pressure at a constant rate in an infinite acting reservoir: When the log-log plot is defined in a pan system, the reservoir properties are easily worked on.

From the Log-log curve, the effects of inner boundary (skin and wellbore storage), the early time region (ETR), radial flow in the middle time region (MTR), and the outer boundary such as faults in the late time region are seen. When the well is first opened to flow after a shut in a certain period of time, the flow rate at that moment is not from the