Doctoral Dissertations

Keywords and Phrases

Average reservoir pressure; Gas initial in place; Oil initial in place; Pseudo pressure and time; Production data; Reservoir


"Production data analysis is an important tool for estimating important reservoir parameters. In particular, determining the average reservoir pressure (pav) and tracking its change with time is critical to analyzing and optimizing reservoir performance. The traditional method for determining pav involves pressure buildup tests. A direct method for estimating (pav) from flowing pressures and rate data is available. However, the method is for an idealized case that assumes constant production rate during pseudo steady-state (PSS) flow, which is not generally true for real wells. This research extends that approach so that it can be used to analyze field data with variable rates/variable pressures during boundary-dominated flow (BDF). For gas reservoirs, pseudopressure and pseudotime functions are used to linearize the gas flow equation and enable the liquid diffusivity solution to satisfy gas behavior when analyzing gas test data. This project investigated when the use of pseudo time becomes necessity, and developed a technique to complete the linearization of diffusivity equation without using conventional pseudo time. A further objective of this research included extending our modified approach into a multi-well system. This modified approach is based on a combination of rate-normalized pressure and superposition-time function. The mathematical basis is presented in support of this approach, and the method is validated with synthetic examples and verified with field data. This modified approach is used to estimate average-reservoir pressure, calculate both connected oil volume and reservoir drainage area as a function of time, and provide a reasonable estimation of the reservoir's shape factor. These calculations, allowing the reservoir performance and management to be properly evaluated"--Abstract, page iv.


Flori, Ralph E.

Committee Member(s)

Dunn-Norman, Shari
Nygaard, Runar
Liu, Kelly H.
Heidari, Peyman


Geosciences and Geological and Petroleum Engineering

Degree Name

Ph. D. in Petroleum Engineering


Libyan Ministry of Higher Education and Scientific Research
Missouri University of Science and Technology


Missouri University of Science and Technology

Publication Date

Fall 2015

Journal article titles appearing in thesis/dissertation

  • Analyzing variable-rate flow in volumetric oil reservoirs


xx, 156 pages

Note about bibliography

Includes bibliographic references.


© 2015 Abuagila Ramadan Elgmati, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Oil reservoir engineering -- Mathematical models
Gas engineering -- Mathematical models
Fluid dynamics -- Mathematical models
Oil fields -- Production methods

Thesis Number

T 10817

Electronic OCLC #