Information Technology Reference
In-Depth Information
overview of the borehole's entire structure is necessary for a higher quality
analysis. This work proposes a novel technique for a precise geometry recon-
struction of the borehole from these data, allowing the geologist to visualize the
borehole, making easier to find possible critical points and allowing an intuitive
visualization of a large set of associated data. The three-dimensional geometry
reconstruction is made from data collected from the caliper log, which includes the
tool orientation and sensors' measures for each section. These measures are used
as control points for the construction of smooth layers, through splines interpo-
lation [
2
]. Finally, the sections are joined in sequence to form a polygonal mesh
that represents a reliable vision of the borehole in three dimensions.
Keywords Well bore model
Oil well visualization
Caliper log
Three-
dimensional visualization
Closed natural cubic splines
13.1 Introduction
Scientific real-time visualization techniques are important tools to understand what
is almost impossible to be seen in numbers. When this visualization approaches are
built into an interactive environment, a powerful workflow is available for the
production and analysis pipeline. In the oil and gas industry, it is always very
important to evaluate the technical and economical feasibility before starting the
drilling process of a gas or oil reserve. The soil structure around the well must be
known, in order to minimize the risks of collapse. The stability analysis of a gas or
oil reserve is a central issue and a challenge for specialists. Good results at this
stage could bring a deep impact in reduction of drilling costs. In the later years,
wells have become longer and with higher inclination making it even more
challenger and expensive.
According to Aadnoy [
3
], for years people have estimated the time loss asso-
ciated with unexpected borehole stability problems to account for 10-15 % of the
time required to drill a well. Since the rig time is the major cost factor in drilling
operation, we understand that borehole stability problems are very costly for the
industry. Borehole collapse is possibly the most costly single problem encountered
during drilling of a well, and there is not a trivial solution for the problem.
This theory states that drilling generates changes in the stress field of the
formation due to supporting material losses, inducing stresses that can result in
more trouble [
4
]. If the stress is higher than the rock strength, rocks can cause the
borehole collapse. So the main fundamental of the solution proposed in this work
is to possibly prevent and reduce instability problems.
The better the planning of a well, the greater are the chances of success to be
achieved. In this context, the word success means achieving the objectives of the
project according to the safety standards of the company, time, and costs consistent
with the ones of the market. However, to achieve this success, Geologists,
Search WWH ::
Custom Search