TDS technique for pressure transient analysis

TDS technique was created by Tiab (1993) and provide a practical solutions using characteristic points reading from a log-log plot of pressure and pressure derivative. It may be use to estimate permeability, skin factor and WBS coefficient without the use of type curves.

Recommended procedure

- Identify the horizontal part of the derivative corresponding ti IARF
- Draw a horizontal line through the IARF data and read the value of the derivative during IARF, \((t* \Delta P')_r\)
- Pick a convenient time, \(t_r\), during IARF and draw a vertical line to intersect the pressure-change curve.
- Draw a horizontal line from the point of intersection of the vertical line to the y-axis, and read the pressure change, \(\Delta P_r\)
- Calculate the permeability from \[ k = \frac{70.6q \mu B}{h(t* \Delta P')_r}\]
- Calculate the Skin factor from \[ s= \frac{1}{2}\left[\frac{\Delta P_r}{(t* \Delta P')_r} - ln \left(\frac{kt_r}{1688* \phi \mu c_tr_w^2} \right) \right] \]
- Draw a unit-slope line through data corresponding to WBS
- Read the coordinates of any point on the unit-slope line \((t,t* \Delta P')\)
- Calculate the WBS coefficient from \[ C = \frac{qBt}{24(t* \Delta P')}\] Image 1

Example: TDS technique in Excel Data from [1]

From image 1, taking the characteristic points and estimate the parameters from the past equations

References

- Spivey, J. & Lee, J. (2013) Applied well test interpretation. Society of petroleum engineers
- Escobar, F.H. (2019) Novel, integrated and revolutionary well test interpretation and analysis

For attribution, please cite this work as

Vazquez (2022, Jan. 23). Chato Solutions: Tiab's direct synthesis (TDS) technique. Retrieved from https://www.chatosolutions.com/posts/2022-01-22-tds1/

BibTeX citation

@misc{vazquez2022tiab's, author = {Vazquez, Rigoberto Chandomi}, title = {Chato Solutions: Tiab's direct synthesis (TDS) technique}, url = {https://www.chatosolutions.com/posts/2022-01-22-tds1/}, year = {2022} }