BOP DRILL STRING AND TUBING STRING MONITORING SYSTEM

SYSTEME DE SURVEILLANCE DU TRAIN DE TIGES ET DE LA COLONNE DE PRODUCTION DANS LE BOP

English Abstract

The system monitors position of a drilling or tubing string coupling in BOP
stack to provide
safe opening/closing of RAM preventers around a drilling or tubing string in
an
underbalance drilling, snubbing or any operation on live wells.
Top sensor device placed under rotary table and above BOP stack consists of 2
sets of
sensors; one detects position of a coupling and the other measures drilling or
tubing string
movement and defines movement direction. Bottom sensor device, placed in
between BOP
stack and wellhead, consists of sensors that detect coupling position.
Information from
sensors is gathered by an electronic controller and sent to a PC with custom
made
specialized software for processing. Processed information is then displayed
on the display
unit as cross-section, or transparent digital image of BOP stack and its
internal elements,
as well as full image of drilling or tubing string and coupling in real time.
Display unit is
positioned conveniently for a driller.

Claims

CLAIMS:
What is Claimed is:

1. A system for monitoring a position of a drilling string couplings in BOP
Stack in
underbalance offshore and onshore drilling and snubbing comprising: a top
sensor
device with two sets of sensors for detecting coupling position and measuring
drill string
movement; a bottom sensor device consisting of one set of sensors for
detecting
coupling position; an electronic controller unit connected to said sensors
through Ex-
Barriers; a PC equipped with specialized monitoring software configured to
process
information received from said controller unit, create the database of drill
string and
generate real-time picture of BOP stack as cross section or transparent image
and drill
string and coupling as a full image; a driller's display on which said real-
time picture is
shown.

2. The system of Claim 1, without the said bottom sensor device.

3. The system of Claim 1, wherein the said top sensor device is separated into
two
independent sensor assemblies; one for measuring drilling movement, the other
detecting the coupling.

4. The system of Claim 1, wherein said drilling string coupling is replaced by
tubing string
coupling in the process of workover, snubbing and other service on live wells.

4

Description

CA 02536451 2006-02-13

BOP Drill String and Tubing String Monitoring System
TECHNICAL FIELD:

The invention pertains to drilling process and weil services. It monitors
position of a drill
string or tubing coupling or cross sectional change in relation to the
ancillary BOP snubbing
stack or to the drilling rig BOP stack in order to provide safe
opening/closing of RAM
preventers above or below drill string or in an underbalanced drilling,
snubbing or any
operation on live wells where snubbing or stripping operations occur.

DESCRIPTION OF PRIOR ART:

To the knowledge of the author's there is no prior art that performs the
function of this
invention.
It is very important to know the exact position of a coupling in BOP stack in
order to provide
safe opening/closing of RAM preventers around a drill string or tubing string.
Establishing
of the exact position of a coupling is performed manually by individual
measuring of drill
pipes.
BOP Drill String Monitoring System possesses numerous benefits and advantages
over
manual procedures. In particular, it provides the driller or snubbing unit
operator with a
cross section formatted, computer generated real-time transparent digital
image of the
snubbing and / or drilling rig BOP stack along with an image of the drill
string or tubing
couplings as related to one another. The driller or snubbing unit operator is
able to track
the movement of the cross sectional change or couplings and to determine their
exact
position in the BOP stack relative to BOP RAM preventors which enables him to
open/close RAM preventers around a drilling string or tubing string in fast,
but safe manner.
Because of the aforementioned, work safety is significantly increased, and
savings in time
and resources are remarkable. Once data regarding pipe geometry / length has
been
entered into the data base, manual measuring of drilling tubulars is no longer
necessary.

1


CA 02536451 2006-02-13
SUMMARY OF THE INVENTION:

BOP Drill String Monitoring System enables on-line monitoring of the coupling
position in
BOP stack. Top and bottom sensor devices detect couplings and cross sectional
changes
as they move past. Data from the sensors is sent to a PC which correlates that
data with
drill string position in relation to the BOP stack. The correlated data is
then processed to
provide a digitalized picture of the drilistring / tubular as related to the
BOP stack. The
geometry of the snubbing BOP or drill rig BOP, including exact positioning of
the BOP
RAMs must be manually entered to tie the correlation between the drill string
tubulars and
the BOP stack. Processed input data and manually entered BOP configuration are
then
generated in to a real-time picture of BOP stack with position of RAMs and the
exact
position of couplings and their movement and it is shown on a driller's
display unit.

DRAWINGS:
Figure 1. - Layout of the system

DETAILED DESCRIPTION OF THE INVENTION:

BOP Drill String Monitoring System consists of four main units (Figure 1.):
top sensor (1)
device, bottom sensor device (2), electronic controller unit (3), PC with the
specialized
monitoring software (4) and driller's or operator's display (5). Top sensor
device (1) is an
electro-mechanical device positioned under the rotary table and above BOP
stack (8). It
consists of 2 sets of sensors; one that detects position of a coupling (9) and
the other that
measures drill string (10) or tubing string (10) movement and it defines
movement
direction. Information gathered is sent to electronic controller unit (3)
through Ex-barrier (6).
Bottom sensor device (2) is flanged between the wellhead (7) and BOP stack
(8). It is an
electronic device that is comprised of one set of sensors that detect coupling
(9) position.
Information gathered is, again, sent to electronic controller unit (3) through
Ex-barrier (6).
Electronic controller unit (3) is a device that collects information from
sensors and sends
the data to a computer equipped with the specialized monitoring software (4)
for further
processing. BOP layout and dimensions are manually entered in the software
(4). Based
on the information entered and data received from top sensor device (1)
computer software
2


CA 02536451 2006-02-13

(4) creates the database of drill string (10) or tubing string (10) and
generates a real-time
picture of BOP stack (8) as a cross section view or transparent image with the
actual
position of couplings (9). Picture of BOP stack (8) and coupling position (9)
is shown on a
driller's or operator's display (5) enabling driller to safely open/close RAM
blowout
preventer (11) around the drilling string (10) or tubing string (10).
Information gathered by
bottom sensor device (2) is used as a safety mechanism that verifies data
logged on in
previous run-in trip of drill string (10) or tubing string (10) during the
running of drill string
(10) or tubing string (10) out of well. If this system is used for running of
drill string (10) or
tubing string (10) out of well without previous run-in trip data available the
information from
Bottom Sensor Device (2) is used together with the data from the top sensor
device (1) to
generate real-time picture of BOP stack (8) with the actual position of
couplings (9).

3

Representative Drawing