Horizontal wells productivity equation under pseudo-steady state (PSS) condition has long been used, while the shape factor (CA) parameter is still obtained from correlation of reported CA tables which are limited on few well and reservoir configurations and not yet verified. Most of the reported CA tables have significant error reaches 92% and overestimates well productivity 32%. Therefore, a comprehensive analysis was implemented and CAs were determined over a wider range of well and reservoir configurations by generalizing pressure transient model of Mutalik, P.N., Godbole, and Joshi, S.D. (1988). A new equation of primary pressure derivative (PPD) based on the generalized model was developed. Five pressure derivative functions (PPD, Slope of PPD, PPD × √TDA, Semi-log PPD (SPPD), Slope of SPPD) were evaluated and analyzed to identify five types of flow regimes (early radial, early linear, late radial, late linear, and PSS) for pressure test analysis. An efficient algorithm was achieved and accurate CAs and their correspondence pseudo-steady state time (TDA)PSS were computed and tabulated. The results show that each of the five flow regimes has identification by a pair of the pressure derivative functions in spite of Slope of SPPD and Slope of PPD functions are considered one function.
|Publication status||Published - 11 Dec 2017|
|Event||2nd EAGE Workshop on Well Injectivity and Productivity in Carbonates 2017 - Doha, Qatar|
Duration: 10 Dec 2017 → 12 Dec 2017
|Conference||2nd EAGE Workshop on Well Injectivity and Productivity in Carbonates 2017|
|Period||10/12/17 → 12/12/17|
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology