The effect of multiple fractures on the performance of gas wells
General Material Designation
[Thesis]
First Statement of Responsibility
K. Mimoune
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
King Fahd University of Petroleum and Minerals (Saudi Arabia)
Date of Publication, Distribution, etc.
1990
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
104
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
M.Sc.
Body granting the degree
King Fahd University of Petroleum and Minerals (Saudi Arabia)
Text preceding or following the note
1990
SUMMARY OR ABSTRACT
Text of Note
A single phase two-dimensional mathematical model was used to predict the performance of a gas intersected by two perpendicular vertical fractures. The fracture half lengths (usdx\sb{f}usd and usdy\sb{f}usd) were assumed to extend equally on both sides of the wellbore. The fractures were assumed to have either infinite or finite conductivities. The analysis of the simulated drawdown tests at constant flow rate showed that the transient flow behavior of a gas well intersected by finite conductivities (usdF\sb� < 500usd) perpendicular fractures does not exhibit neither the bilinear flow behavior nor the formation linear flow behavior when usdy\sb{f}/x\sb{f}usd is greater than zero. Instead it showed that the log-log plot of usdp\sb{D}usd versus usdt\sb{Dxf}usd presented slopes higher than the characteristic slopes of the bilinear and linear flow periods. On the other hand when the fractures conductivities were equal to or greater than 500, the formation linear flow period as observed. The square-root method wa used to determine the fracture half length from the formation linear flow period and found to give a fracture half length that is equal to the sum of the fracture half lengths (usdy\sb{f} + x\sb{f}usd). At early times and for fracture conductivities up to 0.2usd\piusd, the pressure drops, usdp\sb{D}usd, calculated for the case where usdy\sb{f}/x\sb{f}usd = 0.0). But, as the fracture conductivity increased the calculate pressure drops were found to increase to values higher than those for the single fracture cases after some time. This time was found to be a function of fracture conductivity where it decreased as the fracture conductivity increased. The results when plotted as a function of usdp\sb{D}usd versus logusdt\sb{Dxf}usd for both infinite and finite conductivities perpendicular vertical fractures gave, for large usdt\sb{Dxf}usd, a 1.151-slope straight line. Hence, semilogarithmic pressure analysis methods can be applied.