## Abstract

Whenever a well is drilled and completed, it is expected to flow naturally via the wellbore to the surface, a relationship known as inflow and outflow. The inflow performance relationship (IPR) is often required for estimating well capacity, designing well completion, designing tubing string, optimizing well production, performing nodal analysis calculations, and designing artificial lift etc. This performance is commonly defined in terms of a plot of surface production rate versus bottomhole flowing pressure on a cartesian coordinate. The maximum flow rate that occurs when the bottomhole flowing pressure is zero and the maximum rate corresponding to this pressure is called the absolute open flow (AOF). In this chapter, several mathematical models for estimating the inflow performance relationship (IPR) are presented with solved example questions. Also, a case study of an improvement in IPR curve of well K35 to evaluate the efficacy of a pre and post stimulation job is also presented. Result indicates that; it is very important to determine the type of skin on each well. This help in knowing the type of solution to the problem of a well in order to increase its productivity. Thus, a well whose skin is due to completion, partial penetration or slanting of well does not require stimulation and if the field’s operators go ahead to stimulate, they will only end up wasting time and money without achieving any result because these types of skin cannot be removed by stimulation.

## Keyword

Well stimulation Fetkovich Productivity index Skin Inflow performance relationship Absolute open flow Oil rate Formation damage Bubble point pressure Vogel Bottomhole flowing pressure Saturated reservoir Undersaturated reservoir Flow test data## References

- Al-Hussainy R, Ramey HJ Jr, Crawford PB (1966) The flow of real gases through porous media. J Pet Technol 18(5):624–636CrossRefGoogle Scholar
- Bendakhlia H, Aziz K (1989) IPR for solution-gas drive horizontal wells. Paper presented at the 64th annual meeting in San Antonio, Texas, 8–11 Oct 1989Google Scholar
- Cheng AM (1990) IPR for Solution Gas-Drive Horizontal Wells. SPE Paper 20720, presented at the 65th Annual SPE meeting held in New Orleans, September 23–26.Google Scholar
- Craft BC, Hawkins MF, Terry RE (1991) Applied petroleum reservoir engineering, 2nd edn. Prentice-Hall Inc, Englewood CliffsGoogle Scholar
- Dake LP (1978) Fundamentals of reservoir engineering. Elsevier Science Publishers, AmsterdamGoogle Scholar
- Fetkovich MJ (1973) The isochronal testing of oil wells. Paper presented at the SPE 48th annual meeting, Las Vegas, 30 Sept–3 Oct 1973Google Scholar
- Giger FM, Reiss LH, Jourdan AP (1984) The reservoir engineering aspect of horizontal drilling. Paper presented at the SPE 59th annual technical conference and exhibition, Houston, Texas, 16–19 Sept 1984Google Scholar
- Golan M, Whitson CH (1986) Well performance, 2nd edn. Prentice-Hall, Englewood CliffsGoogle Scholar
- Guo B, Ghalambor A (2005) Natural gas engineering handbook. Gulf Publishing Company, HoustonGoogle Scholar
- Klins MA, Majher MW (1992) Inflow Performance Relationships for Damaged or Improved Wells Producing Under Solution-Gas Drive. SPE Paper 19852. JPT, 1357–1363 Dec 1992.Google Scholar
- Klins M, Clark L (1993) An improved method to predict future IPR curves. SPE Res Eng 8:243–248Google Scholar
- Lea JF, Nickens HV, Mike R (2008) Gas well deliquification wells, 2nd edn. Elsevier, BostonGoogle Scholar
- Lee WJ, Wattenbarger RA (1996) Gas reservoir engineering. In: SPE textbook series. Richardson, TexasGoogle Scholar
- Lyons WC, Plisga GJ (eds) (2005) Standard handbook of petroleum and natural gas engineering, 2nd edn. Elsevier, OxfordGoogle Scholar
- Muskat M, Evinger HH (1942) Calculations of theoretical productivity factor. Trans AIME 146:126–139CrossRefGoogle Scholar
- Standing MB (1970) Inflow performance relationships for damaged wells producing by solution-gas drive. JPT 1970:1399–1400CrossRefGoogle Scholar
- Tarek A (2010) Reservoir engineering handbook, 3rd edn. Elsevier Scientific Publishing Company, AmsterdamGoogle Scholar
- Vogel JV (1968) Inflow performance relationships for solution-gas drive wells. Trans AIME 243:83–91Google Scholar
- Wiggins ML (1993) Generalized inflow performance relationships for three phase flow. Paper presented at the SPE production operations symposium, Oklahoma City, 21–23 Mar 1993Google Scholar