Note: Descriptions are shown in the official language in which they were submitted.
. ~0~4~4~
. .
:
. " . .
~ Unconsolidated formations whexe heavy oil or tar
-~. is the matrix have hindered the production in oil wells as
.~-
-well as water wells ever since wells have been drilled.
Early assumptions were that the sand in the oil had to be
~., .
lived with. Curtailed producing rates were sometimes used
:~ to alleviate sand production.
. ~ The problem in tar sands is the undesirable
production of sand with ~t~he oil or bitumen which is
detrimental to most equipment, and particularly to the
pumps.
Unconsolidated or poorly consolidated sands or
.. .- .
; ~; formations are a significant probIem to a great degree,
particuiarly in Canada, Texas, Louisiana, and California, on
both land and offshore. Sanding is a problem all over the
world from the Gulf of Mexico to Venezuela to Nigeria.
Different methods for controlling the migration of
sand from unconsolidated formations or tar sands are
screens, gravel packs, or agglomerating the formation in
place with chemicals. The instant disclosure utilizes a new
combination of the above.
U.S. Patent 3,379,247 circulates hot fluids
between lower and upper perforations in a tar sand
formation, but it also produces sand with the melted bitumen
~25~ which is detrimental to most mechanical equipment above, as
-~,the hydraulic pumps, etc. Assignee's U.S. Patent 3,913,671
~discloses circulating an aqueous heating fluid with sodium
- -~hydroxide out upper performations and in lower perforations
after packing through a sand pack. But this disclosure
lacks the steps of running a wash pipe through the screen
q~"
' '9 ~J~? ,
--1~
1094447
. ~ .
- with a nozzle on lower end thereof a~d breaXing off the
;~ nozzle for enlarging the screen opening among other method
~, ;.~, .
steps for providing an improved method of sand control and
-- production of bitumen. U.S. Patent 2,905,245 likewise lacks
~:` 5 the screen and gravel pack therewith for providing the
,i; disclosed improved method for hydrocarbon production in tar
~ sands . U. S . Patent 3,910,351 discloses a pile of granular
;~m material around a slotted tube in a cavity, but the granular
,. . .
~- material fills the cavity completely with no provision for
,-; 10 penetration by a screen. U.S. 3,812,913 shows a different
method of formation consolidation wherein a bonding~agent is
applied to the formation.
Ac-ordlngly, a pr mary object of th~s invention 1S
to provide an improved process/for producing petroleum such
as bitumen from a subterranean reservoir of very viscous,
. . .
semi-solid, immobile hydrocarbon material, such as tar
~h '. sands, that is economical, practical, and provides
u~interrupted and continuous recovery of petroleum from the
formation.
.. . i~,
Another object of this invention is to provide an
and sys t em
improved method/for sand control in an open hole type of
completion extending into a subterranean reservoir of tar
sands, that 15 economical, practical, and reliable.
25~ A further ob~ect of this invention is to provide a
nd system
~;~ metho~ for producing bitumen from tar sands that is easy to
operate, comprises ~imple method steps, is economical to
utilize and operate, and is o~ greater efficiency for the
. . .
.i~ production of hydrocarbons.
~ . ~
:
....
~2--
109~447
Other objects and various advantages of the disclosed
process for producing bitumen from tar sands will be apparent
from the following detailed description, together with the
accompanying drawings, submitted for the purposes of
illustration only and not intended to define the scope of the
invention, reference being made for that purpose to the
subjoined claims.
Thus the present invention provides a method of
sand control in an open hole type of completion extending into
a subterranean reservoir to tar sands as unconsolidated
petroliferous formation sands comprising the steps of,
(a) drilling a well to the top of the petroliferous
formation and setting a casing therein,
(b) drilling an open hole section of the well to the
bottom of the petroliferous formation,
(c) setting a screen in the open hole and packing it off
against the casing, the screen being large enough to pass a
majority of the formation sand and small enough to retain a
packing material,
(d) running a wash pipe down into the screen for connecting
to a nozzle at the bottom of the screen,
(e) circulating hot aqueous fluids through the wash pipe
and from the lower end thereof for melting the oil or tar
for forming a cavity of a predetermined size around the screen
and open hole,
(f) removing the nozzle from the wash pipe,
(g) without stopping the flow of fluids into the well,
ejecting a consolidating gravel packing material out the
bottom of the wash pipe into the cavity for forming a
consolidated gravel pack around the screen, and
- 3 ~
1094447
(h) removing the wash pipe and circulating hot fluids out
the screen bottom for secondary recovery production of sand-
free oil and melted tar from the petroliferous formation.
In another aspect the invention provides a method of
said control in an open hole type of completion extending into
a subterranean reservoir of tar sands as unconsolidated
petroliferous formation sand comprising the steps of,
(a) drilling a well to the top of the petroliferous
formation and setting a casing therein,
(b) drilling an open hole section of the well to the
bottom of the petroliferous formation,
(c) setting a screen in the open hole and packing it off
against the casing, the screen being large enough to pass a
majority of the formation sand and small enough to retain a
packing material,
(d) running a wash pipe down into the screen for connecting
to a nozzle at the bottom of the screen,
(e) circulating hot aqueous fluids through the wash pipe
and from the lower end thereof for melting the oil or tar for
forming a cavity of a predetermined size around the screen and
open hole,
(f) removing the nozzle from the wash pipe,
(g) packing a tube midway down into the screen, and
(h) in a continuous uninterrupted sequence ejecting a
consolidating gravel packing material from the upper screen
portion above the packer into the cavity to form a consolidated
gravel pack around the lower screen portion for improved sand
control when producing sand-free crude oil from the unconsoli-
dated petroliferous formation.
In still another aspect the invention provides a system
for forming a cavity in unconsolidated petroliferous formation
- 3(a) -
1094447
sands for producing bitumen from a subterranean reservoir of
tar sands as the unconsolidated petroliferous formation sands
from an open well extending down in to the unconsolidated
petroliferous sand formation comprising,
(a) screen means positioned in the well large enough to
pass a majority of the formation sand and small enough to
retain a gravel packing material,
~ b) high pxessure fluid lateral nozzle means releasable
retractably secured for protrudance below said screen means, and
(c) wash pipe means annularly releasably internally
mounted within said screen means and connected to said high
pressure fluid lateral nozzle means for washing out a cavity
in the sand formation.
In still another aspect the invention provides a
system for producing bitumen from a subterranean reservoir of
tar sands as unconsol~dated petroliferous formation sands
fron an op~n walled well segment extending down in to the
unconsolidated petroliferous sand formation comprising,
(a) screen means positioned in the well segment large
enough to pass a majority of the formation sand and small
enough to retain a gravel packing material,
(b) high pressure fluid lateral nozzle means releasably
mounted on and protruding below said screen means,
(c) high pressure fluid wash pipe means releasably
removably annularly mounted in said screen means and connect-
able to said nozzle means for washing out a cavity in the
sand formation,
(d) said high pressure fluid wash pipe means being
replaceable with a production tube means,
(e) said production tube means being packable intermediate
the ends of the screen for forming an annulus means in the well
and screen means, and ~
~ 3(b) -
:, ~ , : ,
1094447
(f) said production tube means comprises means for
ejecting a consolidating gravel packing material from the
screen means upper portion above the packer into the cavity
for forming the consolidated gravel pack around the screen
means lower portion for improved production of bitumen from
the consolidated petroliferous formation sands.
The drawings diagrammatically illustrate by way of
example, not by way of limitation, one embodiment for carrying
out the method and of a system for producing bitumen from tar
sands wherein like reference numerals have been employed to
indicate similar parts in the several views in which:
FIG. 1 is a schematic vertical sectional view of a
well through a subterranean reservoir of tar sands illustrating
one of the first steps of setting a screen in the open hole
down through the tar sand formation to the bottom thereof and
packing it off against the casing;
FIG. 2 is the well of FIG. 1 after a wash pipe has
been run through the screen for connecting to a nozzle at the
screen bottom;
FIG. 3A is the well of FIG. 2 after the cavity has :
been washed out with a horizontal nozzle and a weight is
dropped to break away the nozzle;
FIG. 3B is the well of FIG. 3A with the nozzle broken
out for ejecting a consolidated gravel pack material;
FIG. 4 illustrates injection of the consolidated
gravel pack material;
FIG. 5 illustrates the well producing primary crude
oil; and
- 3(c) -
, .
-` ~094447 :~
FIG. 6 illustrates a gravel pack in the well ~ `
consolidated around the screen by various consolidating
materials as hot aqueous fluids, a jell, or other consolida-
ting chemicals for secondary recovery production. ~ t
~ - 5 The invention disclosed herein, the scope of which E~`
,, being defined in the appended claims, is not limited in its -~
; ` a?plication `to the details of construction and arrangement
;, - - ~ of parts shown and described for carrying out the ~isclosed
:~ - methods, since the invention is capable of other embodiments
and systems for carrying out other methnds and of being
- practiced or carried out in various other ways. Also, it is
to be understood that the phraseology or terminology
employed herein is for the purpose of description and not of
limitation. Further, many modifications and variations of
the invention as hereinbefore set forth will occur to those -
skilled in the art. Therefore, all such modifications and ~^
variations~whlch are within the spirit and scope of the in-
vention hereln are included and only such limitations should
be imposed as are indicated in the appended claims.
. . . and system .
This invention comprises at least one method/for
producin~ bitumen from tar sands.
One aspect o this inven~ion is the production and
25~`recovery of viscous petroleum or bitumen from subterranean
viscous petroleum-containing formations including tar sand
formation by contacting these immo~ile hydrocarbon deposits
Y~ - in the formation near the production well to facilitate '.~;`
removal thereof from the formation. Thus in greater detail, ~;
~'i 30 one method comprises the process steps of: ~~
r',
.'',~s
~.
~ 4- ~
1~ 47 ~' `
`~ (1) setting a screen in an open bole, the screen
being large enough to pass a majority of the formation sand
` . and small enough to retain a packing material as illustrated
in FIG. 1,
. 5 (2) running a wash pipe through the screen for
, connecting to a horizontal nozzle in a hole in the bottom of
~,~ the screen for washing out a cavity around the screen as
r,:~, illustrated in FIG. 2,
.;. (3) pumping a weight down the wash pipe for
~;, 10 breaking off the nozzle for enlarging the screen bottom
. opening as illustrated in FIGS. 3A and 3B, and
(4) without stopping the flow of fluids into the , ~
well, ejecting a consoIidating gravel packing material : c
behlnd the weight through the screen bottom opening for
~ 15 forming a~consolidated gravel pack around the screen for
;~ . primary production as illustrated in FIG. 5, or
: . - (5) e~ecting hot fluids into the cavity after
placement of a packer for melting bitumen from the tar sands .
.for secondary recovery production as illustrated in FIG. 6,
. 20 or . ~.
6} agglomerating the gravel pack with chemicals
as.by means of resins or with jells for secondary recovery
production as illustrated in FIG. 6. ~ .
- In greate~ details the above method may be
2~ expanded to the following steps: .
- (i) drilling a well to the top of the .
petroliferous. formation and setting a casing therein (FIG. ~;
1), ,,~
~2) drilling an open hole section of thè well to
the bottom of the petroliferous formation (FIG. 1),
'~
~ _5_
' ' '
~`` 109~447 ~~
.. (3) setting a screen in the open hole and packing
.~ it off against the casing, the screen being large enough to ,
; pass a majority of the formation sand and small enough to
- retain a packing material (FI~. l), .
(4) forming two oppositely facing horizontaI - '
-~ fracturable nozzles on the lower end of the screen (FIG. 1), ,
(5~ running a wash'pipe down into the.screen for
. , connecting to the horizontal double nozzle at the ~ottom of .
- the screen (FIG. 2), , -
- lo (6) lowerlng the nozzlesr wash pipe, and screen
slowly through the depth o the unconsolidated petroliferous
formation with the hot aqueous fluids ejecting from the
nozzles for forming the ,cavlty of the predetermined size ,
around the screen for melting and producing additional tar. ,~
¦ ,; - 15 . and oil`from the iormation,(FIG. 2), '. . ' ;~
7~: without stopping the flow of fluid into the ,.
! - well, pumping a'weight'down in the wash pipe (FIG. 3A),
8) '-breaking'the nozzles from the lower:end of
the screen wit~i the pump pressure for enlarging, the lower ; ~.
- 20 opening in the screen lFIGS. 3A and 3B),
9 ? without stopping the flow of fluid into the -
; well ejecting a consolidating gravel packing material sut
',-' . the bottom of the wash plpe lnto ,the cavity for forming a ,
, ' consolidated 'gravel,pack ar,ound the screen so that the '
25 , packing material will screen-out against the screen while '
the fluid passes through the screen and back to the surface
through the annulus ormed between the wash plpe and screen
(FIG. 4),
. . .
( 10 ) removing the wash pipe and allowing the
primary oil to flow through the gravel pack and screen to
the surface (FIG. 5), and~or .,
'~
--6--
~,
.: ~
" 109~44~ , ~
" `
(11) packing a tube midway down the screen for
circulating hot fluids down the tube, out the bottom of the
screen, through the cavity and adjacent tar sand formation,
through the gravel pack and screen for upward travel through .
- 5 the annulus for recovery at the suxface (FIG. 6), and/or
. Modified step (9) ejecting a conventional jelling ,
~ gravel packing material from the wa.sh pipe into the cavity
for forming a congealed gravel pack around the screen for
maintaining the pack in position (FIG. 6), and/or
: 10 Modified stép (~j injecting a ,consolidating
plastic or resin gravel packing material, such as but not
limited to, Dow Chemical Company's "Sandlock" described in
their booklet 'INo. SDD-5220 Dowell Sandlock Service", down .
the annulus between the tube and casing and out the upper ~.
. 15 screen portion lnto the cavity for forming a plastic
. consolidated gravel pack around the lower screen portion for
-increased sand control in completion of wells extending into
: the unconsolidated petroliferous formation. ~ -
., ' . . -
A system is disclosed for producing bitumen from a
subterranean reservoir of tar sands, as unconsolidated oil ~'
bearing sands from a well having a casing extending down to
.. the tar sand^formation. . -
- FIG. 1 discloses a well 10 having a casing 11 . 25 ~.extending down through the usual shale formation 12 for
example to- a tar sand formation 13, which open hole well
portion 14 in the formation is drilled down to bedrock 15. A .
preferred mechanism for washing out or forming a cavity in
the well through the unconsolidated oil bearing or tar sand ~
30 formation comprises the following elements. A liner screen -~.
~.
~,'
--7--
` 109~47
16, wash pipe 17, FIG. 2, and a hydraulic double nozzle 18,
FIG. 1, for example, which has two 180 oppositely positioned
openings for ejecting high velocity fluids horizontally or
laterally and is rotatable about bearing housing 19, FIG.
2. The nozzle is connected to a cap 16a on the bottom of the
screen 16 with two or more shear pins 20, FIG. 1, for
example. The top of the screen 16 is packed off against the
bottom of the casing and extends down through the tar sand
or unconsolidated petroliferous formation 13 to the bedrock
for example. This screen is large enough to pass a majority
of the formation sand and small enough to retain a gravel
packing material.
Following packing of the screen in the open hole,
a wash pipe 21, FIG. 2, is lowered internally of the screen
16 to connect to the bottom of the screen and accordingly to
the double nozzle 18. The high pressure fluid supply wash
pipe 17 extends from a suitable source 21 on the surface of
high pressure, high velocity, hot aqueous fluids, as hot
water, down through the well 10 to the cap 16a and the
hydraulic double nozzle 18. Nozzle 18 has two 180
oppositely positioned openings for ejecting the high
velocity fluids horizontally and is rotatable about bearing
housing 17. Thus as the double nozzle ejects hot and high `^
pressure, high velocity fluid in the tar sand formation
immediately under the lower end of the casing, the nozzle is
slowly rotated and lowered until reaching the lowermost,
bedrock position illustrated in FIG.2. Immediately upon
ejection of the hot fluids from the nozzle, a slurry 22 of
spent fluids, sand, and bitumen are washed out, pass through
the screen and then up the annulus 23 in the well formed
I .,
--8-- ~
1(~9~44'7
between the wash pipe and the well walls to exhaust through
a conduit at the surface where the bitumen is recovered
therefrom. After a cavity 24, FIG. 2, is formed, the double
nozzle 18 is removed by pumping a ball 25 down the wash pipe
to shear pins 20, FIG. 3A. to knock the nozzle out of the cap
16a in the bottom of the wash pipe and screen.
A predetermined amount of consolidating graded
gravel pack slurry 26, FIG. 4, substantially equivalent to
the amount of sand and bitumen removed when forming the
cavity, is then measured out. Without stopping the flow
of fluids into the well, a stream of the consolidating gravel
pack slurry 26 is pumped down into the cavity 24 from out
the bottom of the cap 16a and the wash and packing materials
supply pipe 17. The gravel pack slurry circulates up and
around in the cavity 24 to deposit on the screen 16 forming
the consolidated gravel pack 26a. The liquid portion of the
slurry _ passes through the screen and up the annulus 23
to exit from pipe 27 at the surface.
The wash pipe 17, FIG. 4, is then removed and
replaced with an oil outlet pipe 28, FIG. 5, packed in the
casing _. Exit pipe 27, FIG. 4, is removed and the opening
on top of the well sealed with a cap 29, FIG. 5. Primary oil
then flows through gravel pack 26a and into screen 16 for
passage through the oil outlet pipe 28 to the surface for
gathering and/or storage.
When the primary oil ceases to flow, secondary
recovery is required for continued oil production.
Production tubing 30, FIG. 6, is then substituted for the
oil outlet pipe 28, FIG. 5, and packed off midway down the
screen 16 with packer 30a so that oil entering the lower
.,
; .
_g_
~ ~ ~ .
~; .
~'~ half of the'screen may flow, as by being pumped, up through
the production tubing'30 to the surface for gathering and/or
' storage. An injection tube 31 is inserted in the opening
. formerly closed ~y cap 29 for in~ecting secondary recovery'
' .-5 fluids, such as hot-agueous fluids including steam, either'
.7. '. - satùrated or superheated, or hot water, etc. -
.~ - Accordingly, in configuration of FIG. 6~ the high
pressure hot a~ueous fluids~are supplied from a suitable
- source on the surface for-passing through injection tube 31
:10 to the well' casing ll and ànnulus-bet~een.the screen and
: -. -productio.~ ~ubing, through the upper perforated portion of
'.the screen above the packer 30a through which the hot fluids
' . ' .. are ejected.into the well cavity 24 for first spreading the
gravel pack out and below the level of the packer 30a. Then
.lS 'the hot aqueous fluids melt and flow the melted bitumen and
. ' .~ tar.sands -from the tar sand formation through the gravel
.pack 26a toward the screen 16. Only the melted bitumen and
:'wash flui~s pass through'the gravel pack and screen, to the
' production tube for passing up ~ ough the production string
30 to the collection tank at the surface.
. ' . A typical formation with the completed consolida-
ted graveI pack 26a is illustrated in FIG. 6 for a 2-i~nch
. diameter production tube. Here the oil bear1ng formation is
20 feet (6 meters) thick and the gravel pack 26a has a height
- 25~. of 6 feet (1.8 meters) and a radius of 15 feet (4.5 meters).
.. ~ .
The volume is about.4200 cubic feet (120 cubic meters).
In tar sand formations as unconsolidated oil.
bearing sands, the conventional gravel pack is required to
be consolidated to prevent oil sand flow which results in
:~30 low oil flow and provides too low oil flow for good
. .
; ;..;
10--
,. , ! ,
- . ~`..,' -f,.
1~)9~447 ~: ~
.
. . ~ ,. ~
commercial production. This invention overcomes this
problem by consolidating the gravel pack. ,~,r,~
In a modified system the gravel pack in FIG. 6 may
be consolidated or congealed with a conventional jell.
5Another modified system may utilize a gravel pack
consolidated with a thermosetting plastic or resins, such as
but not limited to, that disclosed in U.S. Patent 3,297,086.
Accordingly, it will be seen ~hat a mèthod for
producing bitumen from tar sands has been described which ~
will operate in a manner which meets each of the objects set ~ -
fcrth hereinbefore. .
While only a few methods of the invention have
been disclosed, it will be evident that various other
methods and :modifications are possible without departing
from the scope of the i~nvention and it is accordingly
desired to comprshend with1n-the purview of this invention
such methods and modificatlons as may be considered to fall
within the scope of the appended claims.
~,'.
,' ' " ' '~
~.
~'
