Basalt is classified as a isotropic rock in according to its mechanical
properties. But gypsum is considered isotropic transverse rock . coming
the mechanical parameters values joins practice direction of parameters
.
By using a nondestructive me
thod such as the ultrasonic test which
depends on understanding the effectual of mechanical properties upon
speed of ultrasonics inside rocks , one can indirectly predict the
mentioned parameters
Tests were completed within 35 gypsum and 11 basalt rocks specimens
which collected by completions under the direction of General
Organization for Land Development ( Directorate of Geological
Investigation).
In this article we studied two types of teeth, spherical and
conical one. We compared the results with a previous study for the
flat tooth. the study of stresses field under these three teeth show
that in the soft rocks we prefer to use conical to
oth because it is
easy to be Implanted in the rock, and this was confirmed by the
values of stresses under the tooth. Either in hard rock and due to
our need for big values of pressure to shatter the rock we prefer to
use spherical tooth because of its property of forming tow cons of
stresses under tooth and therefore can be good in drilling hard
rock..
We have
provided in this paper an attempt to study the deformation of oil
wellbore using modeling because of its capability to analyze the
different hypotheses which give us a vision of what is happening
or could happen . We have built a model of
the phenomenon being
studied are expressed in a horizontal section of the oil well on the
geological layer , after loading forces and stresses, we analyzed the
results ( deformations ) for the sandstone ( elastic rock ) and clay
(plastic rock ), where it is shown- by making a hypothesis fit with
abnormalities in the state of the stresses in the oil fields - that the
anomalies in the state of stresses of principles geological stresses
plays an important role in the deformation of oil wellbore.
