Workshop Was held in LPI on Wednesday, 1/4/2009
Title:
“Well Testing with a Permanent Monitoring System &
OVERVIEW OF HIGH-ANGLE AND HORIZONTAL WELL
FORMATION EVALUATION:ISSUES, LEARNINGS, AND FUTURE DIRECTIONS”

Well Testing with a Permanent Monitoring System
By:Mark Tibold , ExxonMobil, Houston Texas
Abstract
An extended welltest was successfully performed on a deep, sour, high-pressure, high temperature remote onshore appraisal well using a permanent downhole monitoring system.

Prior to the six-month extended test an initial test and stimulation
treatment was performed on the well. The permanent
monitoring system provided continuous pressure, temperature
and rate measurement data in a technically challenging
completion environment. Complete and accurate data was
obtained on-line for performance monitoring, reservoir
simulation and analytical test analysis. Unforeseen completion
challenges and wellbore restrictions would have resulted in
alternative conventional data collection methods yielding
severely restricted data suites and test results.


OVERVIEW OF HIGH-ANGLE AND HORIZONTAL WELL
FORMATION EVALUATION:
ISSUES, LEARNINGS, AND FUTURE DIRECTIONS

By David W. Blaisdell , ExxonMobil, Houston Texas

ABSTRACT

High-angle and horizontal (HA/HZ) wells are commonly drilled and often the
logging suite is selected primarily to aid geosteering the well to a
specific target. In many situations, these wells penetrate zones or
portions of the reservoir for which no vertical appraisal wells are
available. In these situations, the logs acquired will be used for routine
formation evaluation of net-to-gross, porosity, and possibly water
saturation. Comparison of log responses in a given formation from vertical
wells to responses in HA/HZ wells indicates that significant differences
can exist. For example, recent studies show that porosity values can be
off as much as 6 p.u., water saturation uncertainty can exceed 50%, and
true stratigraphic thickness can be off by 200-300% because of uncertainty
in apparent dip in highly deviated wells. Thus, routine formation
evaluation approaches for vertical wells may not be adequate for accurate
characterization of formations and fluids in HA/HZ wells.