-
Effects Of Partial Completion On Productivity Index
CHAPTER ONE -- [Total Page(s) 2]
Page 1 of 2
-
-
-
CHAPTER ONE
INTRODUCTION
1.1 PROBLEM STATEMENT
Well
productivity is one of the major concerns in oil field development, and
provides the means for oil field development strategy. Sometimes, well
performance is measured in terms of productivity index. In order to
arrive at the economic feasibility of drilling a well, petroleum
engineers require proven and reliable methods to estimate the expected
productivity of that well. Well productivity is often evaluated using
the productivity index, defined as the production rate per unit pressure
drawdown. Petroleum engineers often relate the well productivity
evaluation to the long-time performance behaviour of a well, that is,
the behaviour during pseudo-steady-state or/and steady-state flow of a
closed system or/and constant pressure system respectively.
The
long-term productivity of oil wells is influenced by many factors. Among
these factors are petrophysical properties, fluid properties, degree of
formation damage and/or stimulation, well geometry, well completions,
number of fluid phases, and flow-velocity type (Darcy, non-Darcy)
(Yildiz, 2003).
Depending upon the type of wellbore completion
configuration, it is possible to have radial, spherical or hemispherical
flow near the wellbore. A well with a limited perforated interval
(partial completion) could result in spherical flow in the vicinity of
the perforations as depicted in fig. 2.1. A well which only partially
penetrates the pay zone, could result in hemispherical flow. These
conditions could arise where coning of bottom water or gas cap becomes a
serious issue (Ahmed, 2005). Figures 3.1 and 3.2 respectively depict
the true picture of radial and spherical flow behaviour in a partially
completed vertical well.
Partial completion is the completion of or
flow from less than the entire producing interval. This situation causes
a near-well flow constriction that result in a positive skin effect in a
well-test analysis. The net result of partial completion yields extra
pressure drop in the near wellbore region and reduces the well
productivity.
CHAPTER ONE -- [Total Page(s) 2]
Page 1 of 2
-
-
ABSRACT - [ Total Page(s): 1 ]A new method for analysing productivity index (PI) on vertical wells is the main objective of this study. Well performance is often measured in terms of the well’s productivity which is dependent on a number of factors such as the reservoir’s configuration, the type of completion, petrophysical and fluid properties, formation damage, etc. The effect of partial completion is the main focus of making the productivity index analysis since almost all vertical wells are partially comple ... Continue reading---
