How to calculate the gas well energy storage coefficient

What does the wellbore storage coefficient represent?

The wellbore storage effect is expressed by the wellbore storage coefficient, C, and is defined as the increase of fluid volume in the wellbore corresponded by the increase of unit BHFP.

What is the primary storage effect in gas wells?

For gas wells, the primary storage effect is due to gas expansion. It should be noted during oil well testing that the fluid expansion is generally insignificant due to the small compressibility of liquids. To determine the duration of the wellbore storage effect, it is convenient to express the wellbore storage factor in a dimensionless form as:

How can a wellbore storage coefficient be compared with a PBU?

Comparing wellbore storage coefficients from several PBUs could help to detect some changes in fluid properties or connected volume. For example, a gas condensate well may see a decrease in wellbore storage, as the condensate drops out in the reservoir and reduce the total compressibility.

How do you determine the flow capacity of a gas well?

Determination of the flow capacity of a gas well requires a relation-ship between the inflow gas rate and the sand face pressure or flowing bottom-hole pressure. This inflow performance relationship may be established by the proper solution of Darcy’s equation.

How do you solve the Theis equation for storage coefficient?

That is, given the value u, we calculated the value of W (u). Using Newtons method we can efficiently calculate u from W (u), and so solve the Theis equation for storage coefficient. Before going further with the well equation, it is worth looking at Newtons method itself as it will be found to have many other applications in groundwater science.

What is the wellbore storage effect?

The wellbore storage effect is expressed by the wellbore storage coefficient, C, and is defined as the increase of fluid volume in the wellbore corresponded by the increase of unit bottomhole flowing pressure (BHFP).