U.S. patent application number 11/209623 was filed with the patent office on 2006-12-14 for method for intercepting and connecting underground formations and method for producing and/or injecting hydrocarbons through connecting underground formations.
This patent application is currently assigned to PETROLEO BRASILEIRO S.A. - PETROBRAS. Invention is credited to Romero Gomes da Silva Araujo, Gabriel Paulo Gutierrez Sotomayor.
Application Number | 20060278396 11/209623 |
Document ID | / |
Family ID | 37523082 |
Filed Date | 2006-12-14 |
United States Patent
Application |
20060278396 |
Kind Code |
A1 |
Sotomayor; Gabriel Paulo Gutierrez
; et al. |
December 14, 2006 |
Method for intercepting and connecting underground formations and
method for producing and/or injecting hydrocarbons through
connecting underground formations
Abstract
The present invention relates to a method for intercepting and
connecting underground formations containing hydrocarbons, so as to
make the production and injection of hydrocarbons technically and
financially feasible in land and offshore oil production zones. It
is claimed to be a method for the production and/or injection of
hydrocarbons through thusly connected underground formations.
Inventors: |
Sotomayor; Gabriel Paulo
Gutierrez; (Rio de Janeiro, BR) ; da Silva Araujo;
Romero Gomes; (Natal, BR) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
PETROLEO BRASILEIRO S.A. -
PETROBRAS
Rio de Janeiro
BR
|
Family ID: |
37523082 |
Appl. No.: |
11/209623 |
Filed: |
August 24, 2005 |
Current U.S.
Class: |
166/313 ; 175/61;
175/62 |
Current CPC
Class: |
E21B 43/305
20130101 |
Class at
Publication: |
166/313 ;
175/061; 175/062 |
International
Class: |
E21B 43/24 20060101
E21B043/24 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 9, 2005 |
BR |
PI 0502087-5 |
Claims
1. Method for interception and connection of underground formations
characterized by the following stages: drill and complete a primary
multilateral well and encase a part of the main well of the
multilateral well, leaving a section of the well open to carry out
connecting operations; drill at least one second multilateral well,
located at a point away from the head of the well of the primary
multilateral well, and encase the main well of the second
multilateral well; intercept the primary multilateral well from the
second multilateral well, by using a proper tool; mechanically
connect the primary multilateral well with the second multilateral
well; finish connecting both of the multilateral wells, allowing
for the produced or injected fluid to drain off from one
multilateral well to the other; produce or inject from one of the
multilateral wells in such a way that the well, (in which
production is not taking place at the moment) is or not closed for
production or injection optimization.
2. Method in accordance with claim 1, characterized by including
the stages of: a) drill a multilateral well to be made according to
the requirements for production area development, which, by using
proper geometry, shall reach at least one subterranean formation,
said multilateral well should have lateral wells connected to the
underground formations. b) encase a part of the main well of
primary multilateral well steel pipes, leaving a section of the
well open to carry out connecting operations; c) complete lateral
wells of the primary multilateral well with a proper filtering
device, after the main multilateral well has been encased; d) drill
at least one second multilateral well according to the requirements
for production area development, which, using proper geometry,
should reach at least one subterranean formation, containing
hydrocarbons. Said subterranean formation should be located at a
point away from the head of the first well of the primary
multilateral well, with a production probe providing support to the
primary multilateral well, said second multilateral well should
possess lateral wells; c) complete lateral wells of the second
multilateral well with a proper filtering device; f) encase the
main well of the multilateral well; g) install a magnetic emitter
in the primary multilateral well to orient the interception of the
primary multilateral well towards another multilateral well; h) to
gain access for the interception from the primary multilateral well
to the second multilateral well, using conventional tools of
navigation with the effect of the magnetic field emitted by the
transmitter located in primary multilateral well; i) leave a fluid
differential, when possible, in order to be aware of the
interception in one of the wells; j) make a mechanical connection
between the multilateral wells; k) finish the well duct (main
well), allowing for the oil fluid to drain off from one
multilateral well another multilateral well; l) produce or inject
both multilateral wells through the second multilateral well or the
primary multilateral well.
3. Method in accordance with claim 2, characterized by a filtering
device such as a cut "liner", cloth, or gravel pack.
4. Method in accordance with claim 2, characterized by a connection
between the wells in Stage (j) to be made using a hollow guide shoe
connected to an external casing packer, which has one end connected
to the primary steel tube used for casing the second multilateral
well.
5. Method in accordance with claim 2, characterized by a connection
between the wells of Stage (j) to be made using a mandril, a set of
wash-cups, and a hollow guide shoe; all connected to the casing
column.
6. Method for producing and/or injecting hydrocarbons through
connecting underground formations, characterized by being carried
into underground formations connected by the method of claim 1.
Description
[0001] This application is based on, claims the benefit of priority
of, and incorporates hereby by reference the contents of Brazilian
Patent Application No. PI 0502087-5 filed on Jun. 9, 2005.
SCOPE OF THE INVENTION
[0002] The present invention relates to a method for intercepting
and connecting underground formations containing hydrocarbons, so
as to make the production and injection of hydrocarbons technically
and financially feasible in land and offshore oil production zones.
It is presented as a method for the production and/or injection of
hydrocarbons through connected underground formations.
FUNDAMENTALS OF THE INVENTION
[0003] To increase the extraction of underground formations
containing hydrocarbons, when possible, wells are drilled
horizontally, vertically, directionally and multilaterally. The
fluid produced from these formations is extracted through the top
of the well and thereafter, through diverse means (pipes, land
transport), this fluid is routed to the refineries. At times, this
strategy becomes impossible in view of current physical, financial,
and technological limits for well construction and/or hydrocarbon
flow. For example, hydrocarbons in zones with water at depths of
3000 m currently cannot be tapped.
[0004] In the past, oil wells were vertically drilled, where the
height of the vertical section of the hydrocarbon formation was
exposed to the oil well.
[0005] Nowadays the technology most frequently used is horizontal
drilling, where horizontal wells are drilled perpendicular to the
vertical axis of the formation, so that a larger area of the
formation may be tapped. The horizontal portion of the oil well
then is called a lateral well.
[0006] In the search for the perfect way to extract oil from a
formation, the oil industry has concentrated on multilateral
drilling, that in general are offshoots drilled from a single
well.
[0007] A vertical, horizontal or directional well is normally
constructed by using drills that cut through the formation until it
reaches the underground formation containing the hydrocarbons or
area of injection, at varying angles, theoretically, from zero
degrees (vertical well) up to ninety degrees (horizontal) passing
through the directional wells (0-90 degrees). These wells are
constructed in stages whose drills and, consequently, the diameter
of the well, have different measurements, that grow smaller as the
well goes deeper. Each Stage of the well is usually encased with a
steel pipe, except in the area of underground formations containing
hydrocarbons where specific equipment is used for oil production or
fluid injection. For example, the drilling of a well may begin by
cutting through the formation with a drill 17.5'' in diameter,
having a steel pipe casing of 133/8'' in diameter and in the next
stage a drill of 121/4'' in diameter may be used, with a steel pipe
casing measuring 95/8'' in diameter. These stages are used in
vertical, horizontal, and directional wells.
[0008] When intercepting underground formations containing
hydrocarbons, the well is equipped to produce said hydrocarbons
through piping connected to equipment located at the head of the
horizontal, vertical, or directional well. Multilateral wells are
also built with steel pipe encased drills, they differ from the
previous ones because they have one or more offset lateral tracks,
that is to say, offshoots built off of the main well. The
construction of this lateral well is made using a diverter that is
located at the main well, said diverter in combination with a
special drill to cut iron, drills through the casing (steel pipes),
creating a lateral opening, from which drilling of the side
offshoot will continue. When the connection between the offshoots
of the lateral wells with the main well becomes interrupted or
obstructed, it can affect the production of hydrocarbons proceeding
from the offshoots or can affect the fluid injection, indirectly
compromising the production of hydrocarbons in the production
area.
[0009] In an attempt to solve problems with mechanical integrity,
U.S. Pat. No. 6,209,648 presents a method and a device to connect
auxiliary columns to a main well, through a mechanical connection,
in order to solve problems with instability of the formation at the
junction. The connection is made by using a recoverable connector
and a casing track, both installed inside the well, which determine
the passage of the production flow.
[0010] Current conventional solutions for developing hydrocarbon
production zones consider using isolated wells (horizontal,
vertical, directional and multilateral wells) of limited scope. The
horizontal wells of great capacity, when the formation allows,
reach a maximum distance of 10 km.
[0011] Recently some alternative concepts have appeared. U.S. Pat.
No. 6,488,087 describe a method for communication of fluid between
a first and second oil well, where one main well intersects a
formation with fractures that extend towards the outer side from
the main well towards the interior of the formation. U.S. Pat. No,
6,488,087 uses sensors in the oil wells to transmit by
electromagnetic sound waves and similar methods indications on the
fluid characteristics in a remote station.
[0012] On the other hand, in U.S. Pat. Nos. 5,923,170 and 5,485,089
methods are presented that determine the distance and direction of
target wells from a well that is being drilled, through the use of
electronic measuring instruments. However, the described methods in
the patents above only deal with determining distances between
parallel wells.
[0013] Therefore, we can verify that the state of the art only
provides instruction for hydrocarbon production from horizontal,
vertical, directional, or multilateral wells, through the well
itself, that is, through the head of the well itself. When this
does not take place, drain off is accomplished through fractures in
underground formations, without an effective interception and
mechanical connection between wells.
[0014] Drilling techniques that determine the distance from one
well to another have been used for drilling parallel wells, and not
for the purpose of draining hydrocarbons from one well to
another.
[0015] Therefore, there is a need in the art for a technical and
economical feasibility in the production and/or injection of
hydrocarbons in land and offshore production zones, where there are
physical, financial, or technical limitations.
SUMMARY OF THE INVENTION
[0016] The present invention proposes, in general terms, a method
for the production and/or injection of hydrocarbons for development
of oil zone production, where two or more wells are mechanically
connected permitting the liquid or injected (injection) fluids from
one of the wells to drain through connected wells.
[0017] Therefore, the main objective of the present invention
provides a method for the interception and connection of oil
wells.
[0018] Another objective of the present invention refers to a
method for the drain off and/or injection of hydrocarbons through
two such connected oil wells.
[0019] The method in accordance with the present invention may be
used in the both land and offshore environments and among other
benefits it may be applied in any formation functioning as a
subterranean duct, draining hydrocarbons from under towns, draining
off heavy oil towards the shallower waters, taking advantage again
of "slots" in fixed platforms, or even reaching injection areas of
difficult access and high cost.
[0020] Furthermore, the method presented in this invention allows
lateral wells, through the installation of completion equipment, to
control its production and/or controlled injection, as well as
receiving equipment to optimize the production or injection.
Lateral wells may be abandoned when necessary. These alternatives
produce a significant cost x benefit ratio in comparison to current
propositions.
[0021] Connecting sub-surface oil wells allows full exploitation of
underground formations to be feasible, substituting or reducing the
number of locations. Also, the method presented in this invention
allows production/injection through fixed production units,
connecting drilled wells such as maritime production units. Said
maritime production units may be fixed or may be semi-submerged
ships so that flowing from the well will take place in fixed
production units. This means a drastic reduction in production
costs and will revitalize financially mature sites. Therefore,
using the method presented by this invention in deep water allows
the production flow of hydrocarbons in deep waters towards
shallower water in the bottom of the well, or that which is done
today at the bottom of the sea through production lines, and
because they are subject to environmental conditions, they create
technical and economical limitations. The method of production of
this invention also makes heavy oil production zone development
economically feasible in deep waters where drilling conventional
wells (horizontal, for example) create limitations.
[0022] By this method, it will also be possible to reduce costs in
zones where environmental limitations do not permit placement of
production units (environmental reserve areas), such as for
example, costal subterranean hydrocarbon formations that may be
tapped by a production unit farther away from the coast with
drilled wells and afterwards have the oil production drained off
through a connection with a drilled well at the land location.
[0023] One of the advantages of this invention is that the simple
connection of two oil wells may easily, with lower risk factors,
reach the exposed area's fold or, when applicable, allow drain off
of the oil over long distances, for example for over a
kilometer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a top view of the production area with interlinked
multilateral wells, in accordance with the present invention.
[0025] FIG. 2 is a side view of the production area with
interlinked drilled multilateral wells, in accordance with the
present invention.
[0026] The modalities of this invention shall now be described, as
an example only regarding the drawings that follow.
[0027] The attached Figures shall be used as numerical references
to designate equal or similar parts.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The method of interception and connection of the wells
proposed by this invention shall now be described as referenced in
FIGS. 1 and 2. It should be noted that the Figures represent the
geometry of the multilateral wells, indeed, this method may be
applied to any type of drilled well through proper geometry, in
order to reach underground formations.
[0029] FIGS. 1 and 2 show the method for interception and
connection of multilateral wells that are composed of the following
stages:
[0030] 1. Drill and complete the primary multilateral well 1;
[0031] 2. Drill at least one second multilateral well 2 located at
a point away from the head of the well of the primary multilateral
well 1, with a production probe providing support to the primary
multilateral well 1;
[0032] 3. Intercept the primary multilateral well 1 from the second
multilateral well 2, by using a proper tool, such as for example, a
magnetic emitter;
[0033] 4. Mechanically connect the primary multilateral well 1 with
the second multilateral well 2;
[0034] 5. Finish connecting both of the multilateral wells 1 and 2,
allowing for the produced or injected fluid to drain off from one
multilateral well to the other;
[0035] 6. Produce or inject from one of the multilateral wells 1
and 2 in such a way that the well, (in which production is not
taking place at the moment) is or not closed for production or
injection optimization.
[0036] The implementation of each of this invention's methods of
interception and connection stages of the multilateral wells will
be described in greater detail below.
[0037] Stage 1
[0038] a) Drill a multilateral well 1 according to the requirements
for production area development, which, using proper geometry,
should reach at least one subterranean formation. In this
prototype, multilateral well 1 reaches underground formations E and
D (also called reservoirs), which contain hydrocarbons.
[0039] As shown in FIGS. 1 and 2, in multilateral well 1 the
lateral wells 1A, 1B have been drilled. These lateral wells 1A, 1B,
connect underground formations E and D.
[0040] b) Encase a part of the main well of multilateral well 1
with steel pipes, leaving a section of the well open to carry out
connecting operations;
[0041] c) Complete lateral wells 1A, 1B of the primary multilateral
well 1 with a proper filtering device, after multilateral main well
1 has been encased. In this stage, proper filtering devices may be
a cut "liner", cloth, gravel pack or similar devices.
[0042] Stage 2
[0043] d) Drill at least one second multilateral well 2 according
to the requirements for production area development, which, using
proper geometry, should reach at least one subterranean formation,
containing hydrocarbons. Said subterranean formation should be
located at a point away from the head of the first well of the
primary multilateral well 1, with a production probe providing
support to the primary multilateral well 1.
[0044] In this prototype, multilateral well 2 reaches underground
formations B and C, which contain hydrocarbons. As shown in FIGS. 1
and 2, in multilateral well 2 the lateral wells 2A, 2B have been
drilled. These lateral wells 2A, 2B, connect underground formations
B and C. If desired, a third multilateral well 3 may still be
drilled, which also will follow the same procedure described
above.
[0045] e) Complete lateral wells 2A, 2B of the second multilateral
well 2 with a proper filtering device. A proper filtering device
would be a cut "liner", cloth, gravel pack or similar device.
[0046] f) Encase with steel pipes the main well of the multilateral
well 2;
[0047] Stage 3
[0048] g) Install a magnetic emitter in multilateral well 1 to
orient the interception of multilateral well 1 towards another
multilateral well, such as for example, multilateral well 2;
[0049] h) To gain access for the interception from multilateral
well 2 to multilateral well 1, using conventional tools of
navigation with the effect of the magnetic field emitted by the
transmitter located in multilateral well 1;
[0050] i) Leave a fluid differential, when possible, in order to be
aware of the interception in one of the wells;
[0051] Stage 4
[0052] j) Make a mechanical connection between the wells using a
hollow guide shoe connected to an external casing packer, which has
one end connected to the primary steel tube used for casing
multilateral well 2. When the entire external packer is positioned
inside the casing pipe of multilateral well 1, said packer will be
inflated so that the insulated polymer will expand and create a
hydraulic seal in the connection. Alternatively a mandril, a set of
wash-cups and hollow guide shoe may be used all connected to the
casing column.
[0053] Stage 5
[0054] k) Finish the well duct (main well), allowing for the oil
fluid to drain off from one multilateral well another multilateral
well;
[0055] Stage 6
[0056] 1) Produce (or inject) both wells through multilateral well
2 or multilateral well 1, for example.
[0057] Once the connection and interception of the wells has been
made, put multilateral well 1 into production so that the oil or
injection may flow from multilateral 2.
[0058] In the method above described, multilateral well 2 may be a
multilateral well with two legs and receive hydrocarbons from a
third multilateral well 3.
[0059] The method for drain off of oil and/or injection through two
interconnected oil wells, in accordance with this invention, is
carried out by draining the oil production from two or more
horizontal/multilateral connected wells, moving towards a well
where the production will take place towards surface
installations.
[0060] In this way, for a given area of deep water oil production,
for example, a set of multilateral wells with two legs can be
defined. Multilateral well 1 may be placed in shallower waters at a
distance of 20 km from the head of multilateral well 2, situated in
ultra deep waters, where it is possible to drill, but not possible
to produce by conventional methods. One of the offshoots (not
shown) of multilateral well 2 is drilled to reach a subterranean
formation containing hydrocarbons in ultra deep waters. The other
offshoot of multilateral well 2 will be connected to one of the
offshoots of multilateral well 1, situated in deep waters where it
can be put into production. The other offshoot of well 1 may be
used, either to connect with the other multilateral well or to
connect with another area with hydrocarbons, or said offshoot may
simply not exist, configuring, in this case, a horizontal well. In
this way the hydrocarbons that are in the zone of ultra deep waters
may drain off from multilateral well 2 towards multilateral well 1,
where it will reach the production facility.
[0061] It should be mentioned that when the original pressure of
the underground formations or from several underground formations
is not sufficient to overcome the loss of load generated during the
oil drain off, pumps may be used to help displace the fluid,
similar to what is currently used in isolated wells (not
connected).
[0062] The pumps may, for example, be installed in junctures
between the multilateral wells. Additional offshoots to the well
duct may be considered, made to come from or to be from
multilateral well 1 or from multilateral well 2 that is closed. The
connecting lateral branches are encased in steel pipes with
hydraulic integrity, including at the connection between the
wells.
* * * * *