May 19, 2003
Summarized Activity Report
Helmi
Al-Jamal,
University of Houston,
Department of Mechanical Engineering
Below is a summary of the current progress of my work.
- The Fourier spectral representation was tested and verified for
accuracy. Although it is accurate in the 2-D simulation, the Chybeshev-Polynomials
representation showed a mathematical inconsistency with it numerical
form which makes it hard to code. However, this problem is possible to
solve using parallel computation. The only valid Chebyshev
representation was the grid transformation method. This transformation
was tested and it gave amazing smoothness especially at the domain
boundries. For being able to apply the parallel computation, I had to
take an extensive course to handle this problem.
- The coding of the vibration governing equations (Stage[4]) is done
and saved to add it to the main code once its accuracy is verified .
- The code is currently being tested for flow field simulation
verification. Since I am applying a completely new approach in building
the flow field domain, some parameters (like the pressure) need to be
fitted to the new domain. I could fit the velocity field and the surface
pressure. I am in the stage of fitting the pressure at the outer
boundaries.
In conclusion, I am currently in the stage of testing the flow
simulation, which is almost Stage [8] in the schedule of the extension
proposal. I still don't have solid results to present, but hopefully to
get done with the verification by this summer to be right on the schedule
as proposed.
May 19, 2003
Summarized Activity Report
Bjorn Gjorv
Texas A&M University
"Well Control Procedures of Extended Reach Wells"
My research can be divided roughly in three parts:
1. Perform a literature search of the state of the art in
well control for vertical, directional, horizontal, extended reach, and
multi-lateral wells.
This is considered to be completed, and was also a part of the
Extended-reach/Multilateral technology workshop held for MMS in November
and December.
2.Use an existing Windows-based well control to model extended
wells. The results gathered from the simulator will be used to evaluate,
compare, and contrast the current well control procedures utilized for
vertical, directional, horizontal, and extended reach wells.
To this date the simulation runs have been completed, I have more
than 350 simulation runs covering a vide range of wellbore trajectories,
different kick-sizes taken in wellbores ranging from conventional wells
to severe extended reach wells in ultradeep water, and also changing the
wellbore sizes. All the results have been saved as excel-files and
presented in charts. My advisor and I are now analyzing the data, and it
is expected that we will complete this within a few weeks.
3. Perform an in-depth study of the multiphase flow
behavior and the flow patterns that can be expected in a horizontal fully
eccentric annuli.
The simulator kind of overestimates the gas removal from the
horizontal section of the well, it assumes that all the gas is removed
in the first circulation, which is not the case in reality. Most of the
literature available related to annular multiphase flow consider a fully
centered annuli, and might not be valid for eccentric annuli, which is
the case in horizontal/near horizontal wells where the pipe lies on the
bottom. There have been some research projects where this has been
modeled, and based upon their mathematical modeling and conclusions I
will estimate what circulation rates will be needed to obtain the flow
pattern that most efficiently removes the gas from the wellbore.
Based on the results of the simulation study, recommendations will be
made to improve well control for any situations that warrant improvement,
especially for extended reach wells.
February 10, 2003
Activity Report
Progress
- Two dynamic drilling tool modeling packages have been evaluated
thoroughly. Unfortunately at this time I don't have full cooperation
from the owner/s so until that time the company name should remain
anonymous and detailed information will be withheld.
- The first modeler is a drill string dynamics package with the
ability to examine lateral and axial modes with respect to frequency and
drillstring location. Shortfalls are that It is not designed for curve
or deviated well bores. It is however a powerful tool for the entire
drillstring in straight and mostly vertical wells.
- The second is a 3D modeler with static and dynamic capabilities in
deviated and curved well bores. As the earlier example it is capable of
analyzing dynamic modes with respect to frequency and location yet can
also analyze the torsional mode. Additionally the static calculations
can be very beneficial not only for build rate, interference and stress
calculations but assists in analyzing what occurs during rotation before
the first mode is realized. It does not like vertical wells and is more
applicable to the BHA as opposed to the entire drillstring.
Interesting findings
- Both methods show first primary modes in the very low frequency
range as expected for an average BHA. Apparently first modes will be
realized often running normal rotary speeds 50-150 rpm.
Next on the agenda.
- Gather vibration data from a case study with BHA information and
begin correlation.
Anticipated problems.
- Full support from modeler and data owner has not yet been granted.
Assurances of non-disclosure of sensitive information and mutual benefit
are the planned debate strategies. In process.
Next update planned 2/7/03
February
15, 2002
Summarized Activity Report for Helmi
Al-Jamal, University of Houston,
Department of Mechanical Engineering
Currently
working on 2-D simulation of the Vortex
Induced Vibrations in Deep Water Risers.
This applies to approximately 30% of the
computational procedure. This information
will give sufficient information to rely on
in checking the results for the proposed
problem, give the proper conditions to be
applied for the problem and become a ready
part of the numerical procedure. The problem
with the 2-D simulation is the loss of
parameters, primarily the interaction
between the flow field and the riser along
its span. This interaction is unpredictable
and non-uniform because the higher harmonics
appear due to the riser’s vibration. The
goals are to determine how the riser will
vibrate, the parameters affecting the
vibration like pretension and end
conditions, the number of harmonics to be
excited and to predict the cyclic loads and
their magnitudes to calculate fatigue life
of the risers.
Update
12/6/01
In
2001 the Houston Chapter of AADE elected to
support a graduate study program at some of
the area universities. It was decided that
the Houston Chapter would offer assistance
in the amount of $20,000.00 to a program or
programs were thought to have significant
technical merit in the area of Well
Construction. A committee was formed and Mr.
John Peters of ChevronTexaco was selected as
Committee Chairman. John asked of volunteers
to assist him in this endeavor and was
joined on the committee by Mr. Jeff Hughes,
Mr. Richard Vernotzy, Mr. Tom Carter and Mr.
Dub Shook.
After the committee was organized, criterion
were established and an offering letter
requesting graduate student proposals was
sent to four (4) universities. These
universities included The University of
Texas, Texas A&M University, Rice
University and The University of Houston.
From this offering the committee received
six (6) proposals from students competing
for grant monies. Each of the six (6)
proposals were independently evaluated by
the members of the committee utilizing the
criterion set out in original offering
letter. The evaluations were then compiled
and the committee made the decision to offer
two (2) grants in the amount of $10,000.00
each.
The two (2) winners of the graduate study
programs were Mr. Helmi Al-Jamal of the
University of Houston, Mechanical
Engineering Department, with his proposal
entitled “A Study of a Drilling Riser
Subjected to Vortex-Induced Vibration” and
Mr. Ray Tommy Oskarsen of Texas A&M
University, Petroleum Engineering
Department, with his proposal entitled “An
Evaluation of Various Dual Density Drilling
Methods”.
Both of these students will be extended
invitations to attend the Las Vegas Night
fund raiser scheduled for January 26, 2002
at the Westin Galleria Hotel in Houston,
Texas. In addition, both of these students
will be asked to present the results of
their studies at one of the upcoming AADE
Spring Technical Conferences. As a part of
this support, both of these students will be
required to submit regular status reports on
their progress. We hope to post these
reports on the Houston Chapter AADE web site
for the entire membership to review.
|
