THE ALGORITHM OF
OPERATIVE RECOGNITION OF ANOMALOUSLY HIGH PRESSURE OF A LAYER IMMEDIATELY
DURING SLOTTING
Anomalous high pressure of
a layer (AHPL), met during drilling, represent serious danger to chisel team,
for the process equipment and environment, since the opening of a layer with
AHPL, considerably exceeding pressure of a pole of a washing liquid results as
a rule in catastrophic wastes, the danger of which is aggravated by suddenness
of its development. In this connection forecasting of possible zones of AHPL is
one of the urgent problems in drilling of petroleum and gas chinks. Know-how on
algorithm is not patented. The joint registration of the international patent
is necessary.
The algorithm of operative
recognition of AHPL directly in process of slotting has such important
significance at the realization of chisel activities, that unwillingness use it
can be followed by tragedy for people, environment and heavy damage to the
business. The conventional method of operative forecasting of AHPL zones in
process of slotting is the method of forecasting till a curve of change of
generalized parameter of drillability d with depth L (d-exhibitor). The average
generalized parameter dav is determined for each 25 m of footage. The
schedule of change in logarithmic scale d (L) is under construction. The line
passing through points, describing dav, is a line of normal
condensation of clay. Entering the zone of AHPL parameters are sharply changed
having of insignificant influence to average significances (~1/N, where N -
quantity of points d-exhibitor through each 25 meters). Deviation of parameters
of a plot of reference direct from average points determines a moment of
opening of a zone of AHPL. The actions of team in these cases are determined by
the specifications of drilling.
However, the standard
method has essential defect expressed in its proximity (inaccuracy), caused by
strong dependence of mechanical speed of drilling on many factors, by virtue of
what the definition of the above named generalized parameter is an incorrect
problem, what reduces accuracy and probability of duly definition of a AHPL
zone.
We have developed a method
deprived of defects, inherent to the standard method, that allows to increase
accuracy and timeliness of definition of AHPL.
With help of a number of
indirect parameters accompanying process of introduction of chisel in a rock the
algorithm allows to determine a moment of approach of chisel to a AHPL zone,
i.e. before opening a layer, that allows to take necessary measures in time and
to prevent catastrophic waste of petroleum (gas) and to avoid ecological
accident, which can endanger live of people. The solution of a problem is
especially important for drilling by the sea, when the area of a marine
platform is limited and there is a congestion of large number of the
attendants, and liquidation of failure and complications stipulated with AHPL
by the sea is extremely expensive and technically difficult problem.
The economic benefit is
connected to safety of the people, with the costs for recovery of the
environment after emergency waste of petroleum (gas).
The know-how value makes US
$700 thousand.