What is Horner approximation in well testing?
The Horner method is widely used to process the pressure-buildup test data for wells produced at a constant flow rate. Ehlig-Economides and Ramey5 used the method of superposition of continuously changing rates to derive a solution for pressure buildup after constant-pressure flow.
What are the types of well testing?
Five test types are briefly discussed below: Pressure Build-Up, Injection/Fall-Off, Multi-rate, Multiple well, and Closed Chamber.
What is done during a well test?
During well tests, reservoir fluids are produced to the separator at varying rates according to a predetermined schedule. These tests may take less than two days to evaluate a single well or months to evaluate reservoir extent. Test types include buildup, drawdown, falloff, injection and interference.
What is the importance of transient flow equation in well testing?
Gas flow rate is changed, and the resulting change in pressure at the well is recorded as a function of time. Results of gas well PTT can be used for two purposes: to determine reservoir characteristics and to determine gas well deliverability.
What is pressure buildup test?
1. n. [Well Testing] The measurement and analysis of (usually) bottomhole pressure data acquired after a producing well is shut in. Buildup tests are the preferred means to determine well flow capacity, permeability thickness, skin effect, and other information.
What are the two main components of a well test?
Scope and definitions. There are many flavours of well tests and various ways to categorize test types by its objectives, however two main categories only by objectives, these are productivity tests and descriptive tests.
What are four phases of well planned test?
Planning, build-up, implementation, and closeout.
What is an unsteady flow?
A flow in which quantity of liquid flowing per second is not constant, is called unsteady flow. Unsteady flow is a transient phenomenon. It may be in time become steady or zero flow. For. example when a valve is closed at the discharge end of the pipeline.
What is transient well test?
Transient well tests measure changes in reservoir pressure associated with changes in well rates. The pressure transient testing (PTT) method relies on measuring the changes in pressure at the wellbore as a function of time that accompany fluid flow rate changes in the wellbore.
What is a well test?
FUNDAMENTALS::::: • A well test is a measurement of flow rate, pressure, and time, under controlled conditions. While the well is flowing, the quality of the data is often poor, thus the data during a shut-in is usually analyzed.
What are the different types of well tests in Alberta?
This article will concentrate on the analysis of the two most common well test types in Alberta, namely “build- up” and “deliverability” tests. • Build-up test*: To conduct a build-up test, simply shut the well in. It is obvious that a build-up test must be preceded by one or more flow periods.
What information can be extracted from a well test?
The following information can be extracted from well tests: • Permeability – The value obtained from a well test is much more useful than that from core analysis, because it represents the in-situ, effective permeability averaged over a large distance (tens or hundreds of metres).
How is a derivative calculated in well testing?
As in well testing (Mattar, L. and Dean, L., 2008), a derivative is also calculated. The resulting data set is plotted on a log-log plot of the same scale as the type curve, and the data moved vertically and horizontally until a match is obtained with one set of curves. Figure 8.4 shows the type curve match for the data of Figure 8.6.