RE: Baker Hughes4 Mar 2024 08:54
Hi Joe80 - yes I have the most basic understanding of the DST operations and of course they are referenced in the RNS died Feb 5th, quote
:Itumbula West-1 well has successfully completed all wireline logging and drill stem testing ("DST") operations
So my understanding and please correct me if I am incorrect is that the data has all been collected - but I am not so sure about your statement about analysing the data live or indeed whether the matter is as simple as you think.
So I have zero industry knowledge so I thought I would do a quick google search on analysing a DST - here is what I came up with:
1. Review the test objectives and design
Before you start interpreting a DST, you should review the test objectives and design. What are you trying to achieve with the test? What are the expected reservoir conditions and fluid types? How did you select the test interval and duration? How did you control the flow rate and pressure during the test? These questions will help you establish the context and assumptions for your interpretation.
2. Plot the pressure and flow rate data
The next step is to plot the pressure and flow rate data from the DST on a graph. You should use a logarithmic scale for both axes to better visualize the trends and patterns. You should also label the different phases of the test, such as build-up, drawdown, shut-in, and flow. The shape and slope of the pressure and flow rate curves will indicate the reservoir behavior and response to the test
3. Identify the flow regimes and boundaries
A flow regime is a pattern of fluid flow in the reservoir that reflects the geometry and heterogeneity of the reservoir. A boundary is a limit or change in the reservoir properties that affects the fluid flow. You should identify the flow regimes and boundaries from the pressure and flow rate curves by looking for changes in slope, inflection points, or deviations from the expected behavior. For example, a radial flow regime will have a constant slope on a log-log plot, while a linear flow regime will have a unit slope. A boundary can be a fault, a fracture, or a limit of the reservoir.
4. Apply analytical models and equations
Once you have identified the flow regimes and boundaries, you can apply analytical models and equations to estimate the reservoir properties and parameters. Analytical models are mathematical expressions that relate the pressure and flow rate data to the reservoir characteristics, such as permeability, porosity, skin factor, and reservoir pressure. You can use different models depending on the flow regime and boundary conditions. For example, you can use the Horner method for radial flow with a closed boundary, or the Gringarten method for linear flow with a fracture.
to be continued...