Well Testing As Part Of Formation Analysis

2385 Words5 Pages

1.1 Well Testing
Well testing may be regarded as part of formation evaluation. The objective of formation evaluation is to provide input to a geologic model, which in turn may provide important input data for an economic model. Decisions, whether to start possible engineering projects or not, are based on economic analysis.
Classical well test interpretation depends on simplified analytical models and graphical techniques. The methodology may be described as follows: A pressure test is conducted by giving the well at least one perturbation in flow rate. The pressure response (pressure signature) is measured and matched to a mathematical model (equation or graph). Each well has a unique response which depends on the rock and fluid properties. …show more content…

1.6.2 DESCRIPTIVE WELL TEST
When it’s necessary to characterize the reservoir, evaluate a stimulation or fracture treatment, estimate the formation flow capacity, it is required to perform a Transient test.
The transient test is performed by introducing abrupt change in flowing conditions, so a transient response is induced. The pressure disturbance penetrates much further than the near-wellbore region, originating a test called “Descriptive” or “Reservoir testing”. The Descriptive well testing is a refined form of testing, which describes what happens in the reservoir when the pressure changes.
Production changes, carried out during a transient well test, induce pressure disturbances in the wellbore and surrounding rock. This disturbances extend into the formation and are affected in various ways by the rock features. For example, a low permeable rock will restrict the pass of the pressure wave. Therefore, a record of the pressure response over time produces a curve whose shape is defined by the reservoir’s unique characteristics.
1.7 Single And Multi Well …show more content…

The IFO is the exact image of a Pressure Build-Up (PBU) on a producing well and analysis can derive the same types of fundamental wellbore/reservoir information on an injector well that can with a producing well, skin, permeability and reservoir pressure. The main interest in the IFO is to concede skin and its effect on injector. Because we are limited to 0.5 psi/ft. on injection surface pressures, a rising skin will require even higher injection pressures to maintain the same injection rates. At some future point we will be limited by the surface injection pressure limitation, as set by the state, not supervising the increased cost of fueling injection pumps. If the well in query is a Saltwater Disposal (SWD) well, which often have less stringent separation/filter requirements for the injected fluid, skin increment can occur quickly. Knowing your "original" wellbore condition before injection begins and then testing periodically thereafter or when you notice increasing injection pressures would be a good

More about Well Testing As Part Of Formation Analysis

Open Document