#Well drawdown test skin
#Well drawdown test full

Multirate testsĪccounts for variable rate history and applications.Īdvantages No problems with variable flow rate, no loss of production, and reduced wellbore storage. Long shut in so that Pi is achieved is required. Disadvantages Difficult to maintain constant production rate. With No need to lose production, reservoir size can be determined. Shut in the well till pressure reaches static level and then flowing the well at a constant rate ,q & measuring Pwf.Īdvantages Suitable in new wells. This is usually done with a drilling rig on-site, and the string through which the well is produced is manipulated by the drilling rig.Ī drawdown test is one in which the rate is held approximately constant while the well pressure is measured.

#Well drawdown test full

In newly developed reservoirs or high-risk developments it may be worthwhile to test the well before completing it or installing full production facilities.

and are typically run to the desired depth before actuating levers or other devices seal them against the side of the wellbore. To check pressure equilibrium and thus homogeneity wells can be tested using wireline-conveyed tools, either in casing or open-hole. Multi-point tests are used to establish gas well deliverability and absolute open flow potential Single-point tests typically involve a measurement or estimate of initial or average reservoir pressure and a flow rate and flowing bottomhole pressure measurement. Other flow tests, such as single-point tests and multi-point tests, are performed after the well has been cased. A DST is used to obtain reservoir fluid samples, static bottomhole pressure measurements, indications of productivity and short-term flow and pressure buildup tests to estimate permeability and damage extent. Some flow tests, such as drill stem tests (DSTs), are performed in the open hole. Confirming heterogeneities and boundariesĪ Flow test is an operation on a well designed to demonstrate the existence of moveable petroleum in a reservoir by establishing flow to the surface and/or to provide an indication of the potential productivity of that reservoir.Estimating the average reservoir pressure.Identifying heterogeneities and boundaries.

#Well drawdown test skin

Evaluating the well permeability and skin effect.

Non-Darcy coefficient (multirate tests).

Well tests, if properly designed, can be used to estimate the following parameters: To perform a well test successfully one must be able to measure the time, the rate, the pressure, and control the rate. Most well tests consist of changing the rate, and observing the change in pressure caused by this change in rate.