A multi-rate test is a specific type of well test designed to evaluate a well's deliverability characteristics. It helps determine how efficiently a well can produce hydrocarbons under varying flow conditions.
Often referred to as an “isochronal test”, this method involves a structured sequence of flowing the well and then shutting it in.
How a Multi-Rate Test Works
The core principle of a multi-rate deliverability test is to observe the well's behavior at different stabilized (or near-stabilized) flow rates. According to standard practice:
- It requires that a well be flowed and shut in at several different flowrates.
- Typically, the test is performed at 3 to 4 distinct flowrates.
- There are buildup periods between each rate where the well is shut in to allow pressure to recover.
- A crucial requirement is that each flowrate, and corresponding buildup last the same length of time. This ensures consistency in the test procedure and simplifies analysis.
By conducting the test in this manner, engineers can gather data points relating flow rate to pressure behavior, which is essential for predicting future production capacity and understanding reservoir characteristics impacting flow.
