TY  - CONF
PB  - Society of Petroleum Engineers (SPE)
SN  - 9781615670123
EP  - 624
AV  - none
N1  - cited By 1; Conference of 16th Middle East Oil and Gas Show and Conference 2009, MEOS 2009 ; Conference Date: 15 March 2009 Through 18 March 2009; Conference Code:78174
SP  - 609
TI  - Transient pressure behavior for a reservoir with continuous permeability distribution in the invaded zone
Y1  - 2009///
A1  - El-Khatib, N.A.F.
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-70449574783&doi=10.2118%2f120111-ms&partnerID=40&md5=2c768047faaba7802e6b68a2eab018a1
VL  - 2
CY  - Manama
N2  - A mathematical model is presented for a reservoir with a continuous permeability distribution in the invaded zone. An analytical solution of the system was obtained in Laplace space. Solutions in real time space for the pressure and pressure derivative are obtained by numerical inversion of the Laplace transform using Stehfest algorithm. Solutions were obtained for infinite reservoirs and for finite reservoirs with closed and constant pressure outer boundaries. The permeability in the invaded zone varies from a skin permeability Ks at the wellbore to the original permeability Ke at the end of the invaded zone Rs. The effects of the permeability ratio, the depth of invasion, the reservoir size, and the wellbore storage were investigated. Results of this study show that for this permeability distribution, the permeability ratio has a profound effect on the pressure behavior while the depth of invasion plays an insignificant role. It also showed that the use of the average permeability of the invaded zone in the steady state skin equation gives almost identical results of the additional pressure drop due to formation damage at large times as those obtained from the exact solution. An approximate solution can be used for relatively high invasion depths (RSD > 20) which shows that the additional pressure drop is independent of the invasion depth Copyright 2009. Society of Petroleum Engineers.
ID  - scholars797
KW  - Boreholes; Drops; Equations of state; Laplace transforms; Oil field equipment; Oil wells; Petroleum reservoirs; Pressure drop
KW  -  Additional pressure drops; Approximate solution; Average permeability; Infinite reservoirs; Numerical inversion; Permeability distribution; Pressure derivatives; Transient pressures
KW  -  Petroleum reservoir engineering
ER  -