CA2019760A1 - Pipeline transportation of heavy hydrocarbons - Google Patents
Pipeline transportation of heavy hydrocarbonsInfo
- Publication number
- CA2019760A1 CA2019760A1 CA002019760A CA2019760A CA2019760A1 CA 2019760 A1 CA2019760 A1 CA 2019760A1 CA 002019760 A CA002019760 A CA 002019760A CA 2019760 A CA2019760 A CA 2019760A CA 2019760 A1 CA2019760 A1 CA 2019760A1
- Authority
- CA
- Canada
- Prior art keywords
- heavy hydrocarbon
- hydrocarbon product
- heavy
- mixture
- diluent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Abstract
ABSTRACT
A process is disclosed for reducing the viscosity of a heavy hydrocarbon product such as heavy crude oil or bitumen for improved pipeline transporta-tion. Carbon dioxide is introduced into a mixture of the heavy hydrocarbon product and hydrocarbon diluent to yield a reduced-viscosity mixture suitable for pipeline transportation. The amount of diluent needed to yield a mixture of suitable viscosity is reduced by the use of carbon dioxide, and the total volume of liquid mixture required to transport a unit volume of heavy hydro-carbon product also is reduced, thereby improving the economics of pipeline transportation.
A process is disclosed for reducing the viscosity of a heavy hydrocarbon product such as heavy crude oil or bitumen for improved pipeline transporta-tion. Carbon dioxide is introduced into a mixture of the heavy hydrocarbon product and hydrocarbon diluent to yield a reduced-viscosity mixture suitable for pipeline transportation. The amount of diluent needed to yield a mixture of suitable viscosity is reduced by the use of carbon dioxide, and the total volume of liquid mixture required to transport a unit volume of heavy hydro-carbon product also is reduced, thereby improving the economics of pipeline transportation.
Description
2~76~
IMPROVED PIPELINE TRANSPORTATION OF HEAVY HYDROCARBONS
TECHNICAL FIELD
The present ~nventton relates to the p~pel~ne transportatton of heavy crude otl or bttumen, and more parttcularly to a process for reducing diluent requtrements for such pipel~ne transportatton.
:
BACKGROUND OF THE INVENTION
The product~on of heavy crude oil and bitumen will play an important role in future energy supplles ~n many parts of the world. Large depostts ; of these heavy hydrocarbon products extst, for example, in the UnttedStates, Canada, Venezuela, and other countr~es. As the productlon of lighter crude oil decl~nes, part~cularly ~n the Un~ted States and Canada, the productton and transportatton of these heavy hydrocarbon products wtll be of growing long-term tmportance. - --These heavy hydrocarbon products are h~ghly v~scous or even soltd at ambtent temperatures. Heavy crude olls, character~zed by gravtttes between about 12 and 17API, may be fluid at amb~ent temperatures but usually ~ -15 possess viscostttes whtch are too h~gh for econom~cal p~peline transporta-tlon, especially in the winter season ~n colder reg~ons of the world. ~ -B~tumen, character~zed by grav~t~es between about 8 and 12API, ts soltd at ambient temperatures. In order to transport these heavy hydrocarbon products by ptpeltne, it ts common practtce to blend them with ltghter 20 hydrocarbon dtluents so that the resulting m~xture having a ktnemattc vtscostty of about 250 centtstokes or less at ambtent temperature can be transported by ptpeltne to ref~ner~es. Other methods to allow ptpeltne , transportatton of these heavy hydrocarbon products have been used or are betng developed, such as the use of heated p~pel~nes, suspension of these 2S heavy hydrocarbons as emulsions in water, or converting the heavy hydrocarbons to lighter products at the o~l f~eld product~on s~te. The most wtdely used and commercially lmportant method at present, however, is the use of light hydrocarbon dtluents to reduce the viscostties o~ these heavy hydrocarbons. Thts method is expected to be ~mportant in future years as 30 well.
~$ ~
2~9~6~
. . .
The most commonly used d11uent for this purpose is 11ght hydrocarbon condensate from natural gas wells; a typical condensate has a grav1ty of about 60API. Th~s condensate d~luent ~s effect1ve, reasonable 1n cost, and has been in adequate supply. However, as the product10n of heavy crude and b~tumen ~ncreases in the future, ava~lable suppl~es of condensate w111 be ~nsufflc~ent to meet pro~ected requ1rements. Alternate d~luents such as llght crude oil or l~ght hydrocarbon fract~ons obta~ned 1n the ref1n1ng of crude o~ls can be used ~n place of condensate if suff~c~ent suppl1es of these alternates can be obtained at reasonable cost. Another solut10n to l~ d11uent shortfall ~s to recyc1e d~luent from ref1ner~es by p1pel1ne back to the o~l product~on f~eld for reuse. The development of economlcal alter-nat1ves to the use of hydrocarbon d~luents, espec~ally condensate d11uent, and the development of methods to reduce d~luent requ~rements for p1pel1ne transportation of heavy crude o11 and b1tumen, wlll be 1mportant to the }5 future supply of these heavy hydrocarbons as econom~cally v1able energy sources.
In a paper ent~tled In S~tu Development at Marguerite Lake presented at the Alberta 0~1 Sands Technology and Research Author~ty s Advances ~n Petroleum Technolog~ Con~erence, Calgary, Alberta, May 30-31, 1983, R. R. Capel1ng descr~bes the recovery of heavy o11 and b~tumen from the Cold Lake reg~on of Alberta. A process flowsheet ~s presented descr1b1ng the lntroductlon of d~luent to reduce the v~scos~ty of these heavy hydrocarbons pr~or to p~pel1ne transportat10n.
R. D. Urquhart, ~n a paper ent~tled Heavy 0~1 Transportat~on--Present and Future presented at the F~rst Annual Techn~cal Meet1ng of the South Saskatchewan Sect10n, the Petroleum Soc~ety of CIM, Reg1na, September 15-17, 1985, rev1ews the p~pel~ne transportat~on of heavy o11 and b1tumen produced ~n the Alberta and Saskatchewan provinces of Canada. The problem of gas well condensate d~luent shortages ~s d~scussed and alternatives to the use 0 of condensate d~luents are presented.
In an art~cle ent~tled Development of Heavy 0~1 and Natural B1tumen in Western Canada in the Journal of Canad~an Petroleum Technology, January-February 1987, Montreal, pp. 44-47, W. N. Turner reviews the development of heavy oil and natural bitumen ~n western Canada, and part1cularly at p. 47 ,,.j 6 ~
states the requ~rements for viscos~ty reductlon of these heavy hydrocarbons for pipeline transportation and describes a number of hydrocarbon diluents for use in viscosity reduction.
R. T. Bailey in a paper entitled The Heavy Oil Dilemma--Problems Solut~ons and Responsib~l~ties presented at the 38th Canadian Chemical Engineering Conference October 2-5 1988 Edmonton Alberta reviews problems in heavy o~l production and pipeline transportation in Alberta and in particular ~n Figure 6 presents pro~ect~ons of diluent ava~lab~ y and the future shortfall thereof. The availability of the currently favored diluent gas field condensate ~s projected to decline from about 100 000 bbl/day ~n lg90 to about 50 000 bbllday in 2005.
U.S. Patent No. 1 762 423 d~scloses a method for the transportatlon of crude oil and natural gas through a pipeline in which natural gas is com-pressed and cooled the resulting condensate and uncondensed gas are mixed with pressurized crude oil and the resulting m~xture is transported through a p~pellne. The method allows s~multaneous transportat~on of crude oil and natural gas and the v~scosity of the crude o~l ~s reduced which decreases the pu~p~ng power requ~rements.
U.S. Patent No. 3 344 583 d~scloses a method for transporting ethane in a crude oil pipeline by d~ssolving ethane in the crude oil before flow~ng into the pipeline. Methods for d~ssolv~ng ethane and other l~ght hydro-carbons in crude o~l are d~sclosed as are methods for recovering ethane from m~xtures with crude oil after pipel~ne transportatlon.
U.S. Patent No. 3 596 437 d~scloses a method for reducing the viscosity of crude oil in a p~peline by add~ng to the crude oil a fluid containing at least 50% by volume of carbon d~ox~de and less than 10% by volume of ethane. The viscosity of a crude oll at 70F for example can be reduced by at least 30~ when the crude o~l ~s mixed w~th such a fluid. Carbon dioxide for use in this method is generated in part from combustion of natural gas.
U.S. Patent No. 3 618 624 discloses the use of methane ethane carbon dioxide or mixtures thereof for introduct~on into crude oil for viscosity reduction. Carbon dioxide when mixed with crude oil is claimed to promote the format10n of two liquid phases between 40 and 200F and this two-phase 3S .
7 ~ ~
condit~on is preferred for improved pipeline flow of the mixture. The temperature and pressure conditions are controlled in the pipeline to prevent the formation of a gaseous phase therein.
French Patent No. 80 07955 discloses the reduction of heavy oil v~scoslty by d~ssolv~ng carbon d~ox~de ~n the o~l to y~eld a C~/o~l molar rat~o of 0.2 to 0.7 and preferably 0.25 to 0.5. C~ is produced by burning a portion of the crude o~l and recover~ng the C~ from the result~ng combust~on gases. Related~French Patent No. 80 01687 discloses additlonal data and points out that the best results ~n oil viscosity .
;~ 10 reduction are obtained by dissolving 20 to 120 and preferably 25 to 80 cubic meters (S.T.P.) of C~ per cub~c meter of oil.
Japanese Patent No. J60069400 discloses the reduction of heavy hydro-carbon viscositles by dissolution of C~ therein. The viscosity of a heavy oil of 15.1 API was reduced to approximately 100 cP at ambient temperature by disso1ution of C~ at about 80 psig.
SUMMARY OF THE INVENTION
The present inventlon is a process for reducing the viscosity of a heavy hydrocarbon product wh~ch at amb~ent cond~t~ons exh~b~ts a fluid viscosity sufficiently high to render p~peline transportation infeasible.
The process comprises m~xing the heavy hydrocarbon product at a super-amb1ent temperature w1th an a~ount of hydrocarbon diluent separating water and noncondens~ble gas from th~s first mixture cool~ng the mixture and adding an additional amount of hydrocarbon diluent heating the resultlng second mixture and contacting this second mixture with a miscible fluid which dissolves ln the m~xture. The resulting reduced-viscosity mixture of heavy hydrocarbon product hydrocarbon d~luent and m~scible fluid is suitable for pipeline transportation.
I Heavy hydrocarbon products amenable to viscosity reduction by the - 30 process of the present invent~on include heavy crude oil having a gravlty between about 12 and 17API and bitumen having a gravity between about 8 and 12API.
In the process of the present invention the second heavy hydrocarbon-diluent mixture is heated to about 80 to 217F preferably y"
976~
about 95 to 166F, by ~nd~rect heat exchange w~th the first heavy hydro-carbon-d~luent mixture. The heated second mixture is then mixed with a misc~ble fluid, preferably carbon diox~de, in a gas-l~quid contacting device such as a bubble-cap tower, packed tower, or other suitable device at a temperature of between about 80 and 217F, preferably about 95~ to 166F, and at a pressure between about 400 and 1200 psig. The carbon dioxide dlssolves 1n the heavy hydrocarbon-d~luent m1xture and thereby further reduces the vlscosity. The final mixture of heavy hydrocarbon product, diluent, and ~issolved carbon dioxide then flows dlrectly to a pipeline ln whlch lt cools by convection or conductlon to normal pipeline temperature, , ;~ ~ or opt~onally is cooled to p~pel~ne temperature before flowing to the pipeiine. The exact temperature and other cond~tions in the gas-liquid contacting device are carefully selected and controlled so that no carbon dioxide can ex~st as a gas at any po~nt in the p~peline. In genera;l, this ; 15 selected contact temperature will be higher than the maximum temperature of ; hydrocarbons flowing in the pipellne.
In one embodiment of the present ~nvent~on, wherein heavy hydrocarbon products are recovered from a hydrocarbon-bearing format1On by an in situ combustion process, the carbon diox~de utll~zed for f~nal v~scosity reductlon as descrlbed above is recovered from the carbon dioxide-contaln1ng combustion gas from the ~n s~tu combust~on process. In an alternate ~- embodiment of the present ~nvent~on, wherein heavy hydrocarbon products are recovered from a hydrocarbon-bear~ng format~on by the injection of steam into the format~on, the carbon diox~de utilized for final viscosity reduction as descr~bed above is recovered from the carbon dioxide-containing ; flue gas of the steam generator wh~ch produces the steam for in~ection.
It is an ob~ect of the present ~nvent~on to enable the improved ,, pipeline transportat~on of heavy hydrocarbon products wh~ch at ambient temperatures possess fluid viscosities too high for pipel~ne transportation.
A feature of the ~nvention is the use of a miscible fluid such as carbon dioxide which is mixed with the heavy hydrocarbon product along with a hydrocarbon d~luent, so that the resulting reduced-viscosity mixture can -be pumped through a pipeline. , 2~ ~760 - .., .; .
An advantage of the invent~on is that the use of a miscible fluid such as carbon dioxide reduces the amount of diluent needed per unit votume of heavy hydrocarbon product to yield a required mixture viscosity for p1peline transportatlon. Another advantage is that the use of a miscible fluid reduces the total volume of m~xture per un~t volume of heavy hydrocarbon compared w~th a mixture of heavy hydrocarbon product and hydrocarbon diluent alone having the same flu~d viscosity. Th~s results in reduced pipeline pumping requirements and operat~ng costs for an existtng pipeline; alter-nately a greater volume of heavy hydrocarbon product can be moved in the pipel~ne for a given operat1ng cost. If a new pipeline is constructed capital costs can be reduced by the process of the present invention for a given flow of heavy hydrocarbon produtt transported.
BRIEF DESCRIPTION OF THE DRAWINGS
15 Fig. 1 is a schematic flow diagram illustrat1ng an existlng process for the preparat~on of heavy hydrocarbon products for pipeline transportatton.
Fig. 2 is a schematic flow d~agram ~llustrat~ng the alternatlve process of the present invent~on for prepar~ng heavy hydrocarbon products for pipeline transportation.
DETAILED DESCRIPTION OF THE INVENTION
The preparation of heavy hydrocarbon products such as heavy oil or bitumen for p~peline transportat~on by m~x~ng the hydrocarbons with a diluent which ~s common pract~ce ~n the heavy o~l product~on industry is ~11ustrated in Fig. 1. Heavy hydrocarbon products (here~nafter also called heavy hydrocarbons) are typically produced from o~l-bearing formations by thermal methods such as in s~tu combust~on or steam ~nject~on. Other production methods also~are used although less frequently than these two methods. Heavy hydrocarbons from a production well field flow through line 1 are heated ~n heater 101 and flow through line 2 ~nto separator 102 from which gas is removed ~n l~ne 3 and some of the water produced with the heavy hydrocarbons is removed ~n l~ne 4. Hydrocarbon diluent 6 is stored in tank 103 and pumped by pump 104 through lines 7 and 8 and is mixed with the ~;," . ;,~ } ~ , 2~76~
heavy hydrocarbons ~n l~ne 5. The mixture flows through line 9 into electrostatic dehydrator 105 where add~t~onal water is coalesced and removed in line 10 and any diluent vapor formed flows through line 11. The dehydrated and gas-free mixture of heavy hydrocarbons and diluent flows through line 12 and into separator 106 where additional d~luent vap~r is removed in line 13 ~s comb~ned w~th vapor ~n line 11 and combined stream 14 is condensed ln diluent condenser 107. Condensed diluent 15 flows into separator 108 where noncondensible gases are removed ~n l~ne 16. Heavy hydrocarbon-diluent mixture flows from separator 106 through line 17 and is pumped via pump 109 through cooler 110 and l~ne 18. Condensed diluent from separator 108 passes through line 19 is pumped through pump 111 and line 20 is combined w~th add~t~onal diluent from line 21 and the combined diluent stream 22 ~s comb~ned w~th heavy hydrocarbon-d~luent stream 18. The resulting heavy hydrocarbon-diluent stream 23 flows into storage tank 112 from where it flows through l~ne 24 to pump 113 wh~ch pumps the final heavy hydrocarbon-diluent stream through l~ne 25 ~nto the p~pel1ne for transportation to a ref~nery. Th~s stream ~s typ~cally at about ambient temperature and at a pipel~ne pressure between about 400 and 1200 psig. The stream typically contains about 0.4 to 0.7 volumes of diluent per unit 2~ volume of the orig~nal heavy hydrocarbons to give a k~nematic viscosity ofless than 250 cent~stokes. Other d~luent/heavy hydrocarbon rat~os can be used depending on the type of heavy hydrocarbons season of the year and other factors.
In the present ~nvent~on the amount of diluent required to reduce the vlscos~ty of heavy hydrocarbons to a certa~n level is decreased by the addition of a miscible flu~d preferably carbon d~ox~de to the heavy hydrocarbon-d~luent mixture. Referr~ng now to F~g. 2 heavy hydrocarbons and diluent are processed in essentially the same manner as described above with reference to F~g. 1 to provide diluent stream 22 and d~luent-heavy 30 hydrocarbon mixed stream 17. The total amount of diluent in streams 22 and -17 however is less for the present invent~on than for the process described above for F~g. 1 as will be clear from the following discussion.
D~luent-heavy hydrocarbon stream 17 at a temperature of about 210 to 215F
is pumped by pump 109 through l~ne 27 is cooled in heat exchanger 114 is .,.i:: . , . . . : .
~ 2~97~
, mixed with dlluent stream 22 and the comblned stream 23 flows into storage tank 112 at a temperature of about 90 to 110F. Mlxed stream 24 ls pumped by pump 113 through llne 26 and heat exchanger 114 where lt ls heated by lndlrect heat exchange w~th hot dlluent-heavy hydrocarbon stream 27 whlch ls s inltlally at a temperature of about 210 to 215F. The now-heated stream 28is contacted wlth carbon dloxide stream 30 between about 80 to 217F
preferably 95 to 166F and between 400 and 1200 pslg ln fluld-fluld contactor 115 where C~ dlssolves ~n the d~luent-heavy hydrocarbon mlxture to yield a reduced-vlscosity stream 31 conta~nlng heavy hydrocarbons dlluentj and C~ whlch flows to a plpeline for transportatlon to a reflnery. Undlssolved gas flows from contactor 115 via 11ne 29.
Optlonally the heavy hydrocarbon-dlluent-C~ mlxture is cooled to about 40 to 100F by flowing through line 32 cooler 116 and llne 33 to the plpeline for transportatlon to a reflnery. The stream typlcally contalns 0-1 to 0.3 volumes of dlluent and 5 to 8 lbs. of C~ per unlt vclume of the origlnal heavy hydrocarbonsj to g~ve a typ~cal k~nematlc viscoslty of less than 250 centlstokes. Other diluent-C~-heavy hydrocarbon ratlos can be used depending on the type of heavy hydrocarbons season of the year and other factors.
EXAMPLE
The process performance of the present ~nvent~on ls compared with existlng process technology ~n the followlng example.
Uslng exlstlng technology sùch as that d~sclosed ln prevlously-clted art'cle by R. R. Capellng bltumen at 7 000 bb1/day ls mlxed with 3 850 bbl/day of condensate diluent to y~eld a b~tumen-dlluent mlxture of 10 850 bbl/day having a k~nematic v~scos~ty of about 175 centlstokes at 55F. Thls bltumen-dlluent mixture ls prepared and sent to a plpellne as ; lllustrated ln Fl;g. 1. For th~s example an 8-lnch pipeline having a length of 100 miles ls assumed~for transport~ng the b~tumen-d~luent mlxture and a 4-lnch plpellne having the same length ls assumed ~or transporting the dlluent from lts source to the blending process site. The bitumen-dlluent mlxture ls pumped to the pipeline at 870 ps~g by transfer pump 113 of Flg. 1 and pumped through the 100-mile p~pel~ne by a number of pumps spaced ,~
g along the length of the p~peline. D~luent ~s pumped from its source to the blending process site by a series of pumps spaced along the 100-mile pipe-line. The net pumping horsepower requlred for the transfer pump product pipeline pumps and d~luent p~pel~ne pumps for th~s example ~s summar1zed ~n Table 1.
In the appl~cation of the present invention as shown ~n Fig. 2 7 000 bbl/day of bltumen ls mlxed wlth 1 540 bbl/day of condensate dlluent and the m~xture 26 ls heated to 95F by ~nd~rect heat exchange with hot bltumen-diluent stream 27 ~n heat exchanger 114. The heated mlxture 28 ls contacted with C~ at about 870 pslg ~n flu~d-flu~d contactor 115 to d~ssolve about 1 335 000 SCFD of C~ in the m~xture. The bitumen-diluent-C~ mixture at about 870 ps~g and 95F flows through l~ne 31 at a rate of 9 240 bbl/day to the pipellne in which the mixture cools to pipel~ne temperature during transportation to a refinery. Optionally the mixture passes through line 32 to cooler 116 where ~t ~s cooled to about 40 to 55F pr1Or to flowing to the p~pel~ne through line 33. The net pumping horsepower for the present invent~on is summarized and compared with the ex1st~ng process ln Table 1.
- :'-, ~
. .: .
: : .
~-- 2~7~
.
Comparison of Existing Process With Present Invention Existing Present Process Invention -:(Fig. 1) ~F~g. 2) Bltumen Flow, bbl/day ~7,000 7,000 Diluent Flow, bbl/day 3,850 1,540 02 required, MSCFD -- 1,335 Total flow to pipeline, bbllday 10,850 9,240 V~scoslty at 55F, centistokes 175 175 Pump1ng requlrements, BHP
Transfer pump 486 414 P~peline product pumps 1,120 816 Plpellne diluent pumps 360 36 Total : 1,966 1,266 ~;: 20 By utlllzlng the process of the present ~nvention, as ~llustrated by this example, an equ~valent amount of b~tumen can be transported at equ~val~nt plpel~ne cond1t~ons with a d~luent requ~rement 60% lower than ~25 that of the exlst~ng process. Th~s advantage of reduced d~luent requ~rement :wlll become more ~mportant as d~luent avallab~ y decreases and dlluent cost increases ~n future years. The example also illustrates that by utllizing the present ~nvent~on, the total volume of flu~d which must be pumped to transport a unlt volume of bitumen or other heavy hydrocarbons is decreased, thus decreaslng the pumping costs for a given mixture viscosity, p~pel~ne dlameter, and p~pel~ne length. In the example, the total mixture volume requ~red in the present invent~on ~s 15% less than that of the existing process, which reduces the total pump horsepower by 36%. The overall economic advantage of the present invention wlll depend on a number - 2~ ~71~
of factors including bitumen or heavy hydrocarbon properties diluent cost C~ cost power cost and the s~ze and length of product and dlluent pipelines.
Bitumen and heavy oil are often produced from hydrocarbon-bearing formations or reservo~rs by thermal recovery methods includ~ng in situ combust~on talso known as f~reflood~ng) and steam ~njection ~also known as steam flooding). In both cases the heat from in situ combustion or steam injection reduces the v~scos~ty of the heavy hydrocarbons in the reservoir thereby caus~ng flow toward producer wells from which the heavy hydrocarbons are produced.
In the in s~tu combust~on process the heavy hydrocarbons are ignited at the bottom of an ~njection well and an oxygen-contain~ng gas is ~njected to sustain combust~on. The heat and product gases from the combustion cause the heavy hydrocarbons to flow to adjacent product~on wells from which heavy hydrocarbons and combustion gases are produced. The heavy hydro-carbons are then treated and m~xed w~th d~luent as earl~er described for transportation by p~pel~ne. The combust~on gases from this process conta~n light hydrocarbons steam carbon d~ox~de and other components. Carbon d~oxide ~s recovered from th~s combustlon gas for ~ntroduction into the heavy hydrocarbon-diluent mixture for further viscosity reduction as d~sclosed in the present ~nvent~on. There are a number of known methods for recover~ng C~ from such a combust~on gas and these include for example chem~cal react~on w~th amine-based solvent solut~ons physical d~ssolution under pressure by methanol or ether-based solvents or phys~cal adsorption processes. For cases in which the 'n s~tu recovery process uses pure oxygen for combust~on the produeed combustlon gas may be su~f~ciently h~gh ~n C~
content to be used directly in contactor 115 of Fig. 2.
In the steam inject~on method steam ~s produced ~n boilers by the combustion of natural gas produced gas or other hydrocarbon fuels and is in~ected into the reservoir which heats the heavy hydrocarbons such that they flow to adjacent product~on wells from wh~ch heavy hydrocarbons and product gases are recovered. In an alternate mode of operat~on steam is injected into a format~on through an injector well for a specified perlod of time. At the end of th~s period steam injection is discont~nued and heavy 2Q~ 9~
hydrocarbons flow into this well and are recovered. In the present ~nven-tion, carbon dioxide is recovered from the combustlon flue gases from the steam boilers for introduction into the heavy hydrocarbon-dlluent mixture for further viscosity reducti:on. C~ can be recovered from the steam boller combustion flue gases by means of the known processes described above.
Thus the process of the present invent~on can be integrated with eithsr of these two thermal methods of produc~ng heavy hydrocarbons by recoverlng the required carbon diox~de from the byproduct combustlon gases produced ~n these thermal production methods. As discussed earlier, th~s recovered C~
is ~ntroduced ~nto the heavy hydrocarbon-d~luent m~xtures under controlled condlt~ons such that no C~ is present as a gas while the heavy hydrocarbon-d~luent-C~ m~xture flows through the p1peline.
Whlle carbon dioxide is preferred for use in the present invent~on, other components wh~ch are gaseous at amb~ent pressure and temperature can be used. These ~nclude methane, ethane, propane, butane, and other low-boillng components wh~ch are present for example in the gases produced w~th the heavy hydrocarbon product ~n the two recovery methods d~scussed above, or are present ~n natural gas. M~xtures of carbon diox~de w~th these other components can also be used as the misc~ble flu~d of the present ~nventlon.
IMPROVED PIPELINE TRANSPORTATION OF HEAVY HYDROCARBONS
TECHNICAL FIELD
The present ~nventton relates to the p~pel~ne transportatton of heavy crude otl or bttumen, and more parttcularly to a process for reducing diluent requtrements for such pipel~ne transportatton.
:
BACKGROUND OF THE INVENTION
The product~on of heavy crude oil and bitumen will play an important role in future energy supplles ~n many parts of the world. Large depostts ; of these heavy hydrocarbon products extst, for example, in the UnttedStates, Canada, Venezuela, and other countr~es. As the productlon of lighter crude oil decl~nes, part~cularly ~n the Un~ted States and Canada, the productton and transportatton of these heavy hydrocarbon products wtll be of growing long-term tmportance. - --These heavy hydrocarbon products are h~ghly v~scous or even soltd at ambtent temperatures. Heavy crude olls, character~zed by gravtttes between about 12 and 17API, may be fluid at amb~ent temperatures but usually ~ -15 possess viscostttes whtch are too h~gh for econom~cal p~peline transporta-tlon, especially in the winter season ~n colder reg~ons of the world. ~ -B~tumen, character~zed by grav~t~es between about 8 and 12API, ts soltd at ambient temperatures. In order to transport these heavy hydrocarbon products by ptpeltne, it ts common practtce to blend them with ltghter 20 hydrocarbon dtluents so that the resulting m~xture having a ktnemattc vtscostty of about 250 centtstokes or less at ambtent temperature can be transported by ptpeltne to ref~ner~es. Other methods to allow ptpeltne , transportatton of these heavy hydrocarbon products have been used or are betng developed, such as the use of heated p~pel~nes, suspension of these 2S heavy hydrocarbons as emulsions in water, or converting the heavy hydrocarbons to lighter products at the o~l f~eld product~on s~te. The most wtdely used and commercially lmportant method at present, however, is the use of light hydrocarbon dtluents to reduce the viscostties o~ these heavy hydrocarbons. Thts method is expected to be ~mportant in future years as 30 well.
~$ ~
2~9~6~
. . .
The most commonly used d11uent for this purpose is 11ght hydrocarbon condensate from natural gas wells; a typical condensate has a grav1ty of about 60API. Th~s condensate d~luent ~s effect1ve, reasonable 1n cost, and has been in adequate supply. However, as the product10n of heavy crude and b~tumen ~ncreases in the future, ava~lable suppl~es of condensate w111 be ~nsufflc~ent to meet pro~ected requ1rements. Alternate d~luents such as llght crude oil or l~ght hydrocarbon fract~ons obta~ned 1n the ref1n1ng of crude o~ls can be used ~n place of condensate if suff~c~ent suppl1es of these alternates can be obtained at reasonable cost. Another solut10n to l~ d11uent shortfall ~s to recyc1e d~luent from ref1ner~es by p1pel1ne back to the o~l product~on f~eld for reuse. The development of economlcal alter-nat1ves to the use of hydrocarbon d~luents, espec~ally condensate d11uent, and the development of methods to reduce d~luent requ~rements for p1pel1ne transportation of heavy crude o11 and b1tumen, wlll be 1mportant to the }5 future supply of these heavy hydrocarbons as econom~cally v1able energy sources.
In a paper ent~tled In S~tu Development at Marguerite Lake presented at the Alberta 0~1 Sands Technology and Research Author~ty s Advances ~n Petroleum Technolog~ Con~erence, Calgary, Alberta, May 30-31, 1983, R. R. Capel1ng descr~bes the recovery of heavy o11 and b~tumen from the Cold Lake reg~on of Alberta. A process flowsheet ~s presented descr1b1ng the lntroductlon of d~luent to reduce the v~scos~ty of these heavy hydrocarbons pr~or to p~pel1ne transportat10n.
R. D. Urquhart, ~n a paper ent~tled Heavy 0~1 Transportat~on--Present and Future presented at the F~rst Annual Techn~cal Meet1ng of the South Saskatchewan Sect10n, the Petroleum Soc~ety of CIM, Reg1na, September 15-17, 1985, rev1ews the p~pel~ne transportat~on of heavy o11 and b1tumen produced ~n the Alberta and Saskatchewan provinces of Canada. The problem of gas well condensate d~luent shortages ~s d~scussed and alternatives to the use 0 of condensate d~luents are presented.
In an art~cle ent~tled Development of Heavy 0~1 and Natural B1tumen in Western Canada in the Journal of Canad~an Petroleum Technology, January-February 1987, Montreal, pp. 44-47, W. N. Turner reviews the development of heavy oil and natural bitumen ~n western Canada, and part1cularly at p. 47 ,,.j 6 ~
states the requ~rements for viscos~ty reductlon of these heavy hydrocarbons for pipeline transportation and describes a number of hydrocarbon diluents for use in viscosity reduction.
R. T. Bailey in a paper entitled The Heavy Oil Dilemma--Problems Solut~ons and Responsib~l~ties presented at the 38th Canadian Chemical Engineering Conference October 2-5 1988 Edmonton Alberta reviews problems in heavy o~l production and pipeline transportation in Alberta and in particular ~n Figure 6 presents pro~ect~ons of diluent ava~lab~ y and the future shortfall thereof. The availability of the currently favored diluent gas field condensate ~s projected to decline from about 100 000 bbl/day ~n lg90 to about 50 000 bbllday in 2005.
U.S. Patent No. 1 762 423 d~scloses a method for the transportatlon of crude oil and natural gas through a pipeline in which natural gas is com-pressed and cooled the resulting condensate and uncondensed gas are mixed with pressurized crude oil and the resulting m~xture is transported through a p~pellne. The method allows s~multaneous transportat~on of crude oil and natural gas and the v~scosity of the crude o~l ~s reduced which decreases the pu~p~ng power requ~rements.
U.S. Patent No. 3 344 583 d~scloses a method for transporting ethane in a crude oil pipeline by d~ssolving ethane in the crude oil before flow~ng into the pipeline. Methods for d~ssolv~ng ethane and other l~ght hydro-carbons in crude o~l are d~sclosed as are methods for recovering ethane from m~xtures with crude oil after pipel~ne transportatlon.
U.S. Patent No. 3 596 437 d~scloses a method for reducing the viscosity of crude oil in a p~peline by add~ng to the crude oil a fluid containing at least 50% by volume of carbon d~ox~de and less than 10% by volume of ethane. The viscosity of a crude oll at 70F for example can be reduced by at least 30~ when the crude o~l ~s mixed w~th such a fluid. Carbon dioxide for use in this method is generated in part from combustion of natural gas.
U.S. Patent No. 3 618 624 discloses the use of methane ethane carbon dioxide or mixtures thereof for introduct~on into crude oil for viscosity reduction. Carbon dioxide when mixed with crude oil is claimed to promote the format10n of two liquid phases between 40 and 200F and this two-phase 3S .
7 ~ ~
condit~on is preferred for improved pipeline flow of the mixture. The temperature and pressure conditions are controlled in the pipeline to prevent the formation of a gaseous phase therein.
French Patent No. 80 07955 discloses the reduction of heavy oil v~scoslty by d~ssolv~ng carbon d~ox~de ~n the o~l to y~eld a C~/o~l molar rat~o of 0.2 to 0.7 and preferably 0.25 to 0.5. C~ is produced by burning a portion of the crude o~l and recover~ng the C~ from the result~ng combust~on gases. Related~French Patent No. 80 01687 discloses additlonal data and points out that the best results ~n oil viscosity .
;~ 10 reduction are obtained by dissolving 20 to 120 and preferably 25 to 80 cubic meters (S.T.P.) of C~ per cub~c meter of oil.
Japanese Patent No. J60069400 discloses the reduction of heavy hydro-carbon viscositles by dissolution of C~ therein. The viscosity of a heavy oil of 15.1 API was reduced to approximately 100 cP at ambient temperature by disso1ution of C~ at about 80 psig.
SUMMARY OF THE INVENTION
The present inventlon is a process for reducing the viscosity of a heavy hydrocarbon product wh~ch at amb~ent cond~t~ons exh~b~ts a fluid viscosity sufficiently high to render p~peline transportation infeasible.
The process comprises m~xing the heavy hydrocarbon product at a super-amb1ent temperature w1th an a~ount of hydrocarbon diluent separating water and noncondens~ble gas from th~s first mixture cool~ng the mixture and adding an additional amount of hydrocarbon diluent heating the resultlng second mixture and contacting this second mixture with a miscible fluid which dissolves ln the m~xture. The resulting reduced-viscosity mixture of heavy hydrocarbon product hydrocarbon d~luent and m~scible fluid is suitable for pipeline transportation.
I Heavy hydrocarbon products amenable to viscosity reduction by the - 30 process of the present invent~on include heavy crude oil having a gravlty between about 12 and 17API and bitumen having a gravity between about 8 and 12API.
In the process of the present invention the second heavy hydrocarbon-diluent mixture is heated to about 80 to 217F preferably y"
976~
about 95 to 166F, by ~nd~rect heat exchange w~th the first heavy hydro-carbon-d~luent mixture. The heated second mixture is then mixed with a misc~ble fluid, preferably carbon diox~de, in a gas-l~quid contacting device such as a bubble-cap tower, packed tower, or other suitable device at a temperature of between about 80 and 217F, preferably about 95~ to 166F, and at a pressure between about 400 and 1200 psig. The carbon dioxide dlssolves 1n the heavy hydrocarbon-d~luent m1xture and thereby further reduces the vlscosity. The final mixture of heavy hydrocarbon product, diluent, and ~issolved carbon dioxide then flows dlrectly to a pipeline ln whlch lt cools by convection or conductlon to normal pipeline temperature, , ;~ ~ or opt~onally is cooled to p~pel~ne temperature before flowing to the pipeiine. The exact temperature and other cond~tions in the gas-liquid contacting device are carefully selected and controlled so that no carbon dioxide can ex~st as a gas at any po~nt in the p~peline. In genera;l, this ; 15 selected contact temperature will be higher than the maximum temperature of ; hydrocarbons flowing in the pipellne.
In one embodiment of the present ~nvent~on, wherein heavy hydrocarbon products are recovered from a hydrocarbon-bearing format1On by an in situ combustion process, the carbon diox~de utll~zed for f~nal v~scosity reductlon as descrlbed above is recovered from the carbon dioxide-contaln1ng combustion gas from the ~n s~tu combust~on process. In an alternate ~- embodiment of the present ~nvent~on, wherein heavy hydrocarbon products are recovered from a hydrocarbon-bear~ng format~on by the injection of steam into the format~on, the carbon diox~de utilized for final viscosity reduction as descr~bed above is recovered from the carbon dioxide-containing ; flue gas of the steam generator wh~ch produces the steam for in~ection.
It is an ob~ect of the present ~nvent~on to enable the improved ,, pipeline transportat~on of heavy hydrocarbon products wh~ch at ambient temperatures possess fluid viscosities too high for pipel~ne transportation.
A feature of the ~nvention is the use of a miscible fluid such as carbon dioxide which is mixed with the heavy hydrocarbon product along with a hydrocarbon d~luent, so that the resulting reduced-viscosity mixture can -be pumped through a pipeline. , 2~ ~760 - .., .; .
An advantage of the invent~on is that the use of a miscible fluid such as carbon dioxide reduces the amount of diluent needed per unit votume of heavy hydrocarbon product to yield a required mixture viscosity for p1peline transportatlon. Another advantage is that the use of a miscible fluid reduces the total volume of m~xture per un~t volume of heavy hydrocarbon compared w~th a mixture of heavy hydrocarbon product and hydrocarbon diluent alone having the same flu~d viscosity. Th~s results in reduced pipeline pumping requirements and operat~ng costs for an existtng pipeline; alter-nately a greater volume of heavy hydrocarbon product can be moved in the pipel~ne for a given operat1ng cost. If a new pipeline is constructed capital costs can be reduced by the process of the present invention for a given flow of heavy hydrocarbon produtt transported.
BRIEF DESCRIPTION OF THE DRAWINGS
15 Fig. 1 is a schematic flow diagram illustrat1ng an existlng process for the preparat~on of heavy hydrocarbon products for pipeline transportatton.
Fig. 2 is a schematic flow d~agram ~llustrat~ng the alternatlve process of the present invent~on for prepar~ng heavy hydrocarbon products for pipeline transportation.
DETAILED DESCRIPTION OF THE INVENTION
The preparation of heavy hydrocarbon products such as heavy oil or bitumen for p~peline transportat~on by m~x~ng the hydrocarbons with a diluent which ~s common pract~ce ~n the heavy o~l product~on industry is ~11ustrated in Fig. 1. Heavy hydrocarbon products (here~nafter also called heavy hydrocarbons) are typically produced from o~l-bearing formations by thermal methods such as in s~tu combust~on or steam ~nject~on. Other production methods also~are used although less frequently than these two methods. Heavy hydrocarbons from a production well field flow through line 1 are heated ~n heater 101 and flow through line 2 ~nto separator 102 from which gas is removed ~n l~ne 3 and some of the water produced with the heavy hydrocarbons is removed ~n l~ne 4. Hydrocarbon diluent 6 is stored in tank 103 and pumped by pump 104 through lines 7 and 8 and is mixed with the ~;," . ;,~ } ~ , 2~76~
heavy hydrocarbons ~n l~ne 5. The mixture flows through line 9 into electrostatic dehydrator 105 where add~t~onal water is coalesced and removed in line 10 and any diluent vapor formed flows through line 11. The dehydrated and gas-free mixture of heavy hydrocarbons and diluent flows through line 12 and into separator 106 where additional d~luent vap~r is removed in line 13 ~s comb~ned w~th vapor ~n line 11 and combined stream 14 is condensed ln diluent condenser 107. Condensed diluent 15 flows into separator 108 where noncondensible gases are removed ~n l~ne 16. Heavy hydrocarbon-diluent mixture flows from separator 106 through line 17 and is pumped via pump 109 through cooler 110 and l~ne 18. Condensed diluent from separator 108 passes through line 19 is pumped through pump 111 and line 20 is combined w~th add~t~onal diluent from line 21 and the combined diluent stream 22 ~s comb~ned w~th heavy hydrocarbon-d~luent stream 18. The resulting heavy hydrocarbon-diluent stream 23 flows into storage tank 112 from where it flows through l~ne 24 to pump 113 wh~ch pumps the final heavy hydrocarbon-diluent stream through l~ne 25 ~nto the p~pel1ne for transportation to a ref~nery. Th~s stream ~s typ~cally at about ambient temperature and at a pipel~ne pressure between about 400 and 1200 psig. The stream typically contains about 0.4 to 0.7 volumes of diluent per unit 2~ volume of the orig~nal heavy hydrocarbons to give a k~nematic viscosity ofless than 250 cent~stokes. Other d~luent/heavy hydrocarbon rat~os can be used depending on the type of heavy hydrocarbons season of the year and other factors.
In the present ~nvent~on the amount of diluent required to reduce the vlscos~ty of heavy hydrocarbons to a certa~n level is decreased by the addition of a miscible flu~d preferably carbon d~ox~de to the heavy hydrocarbon-d~luent mixture. Referr~ng now to F~g. 2 heavy hydrocarbons and diluent are processed in essentially the same manner as described above with reference to F~g. 1 to provide diluent stream 22 and d~luent-heavy 30 hydrocarbon mixed stream 17. The total amount of diluent in streams 22 and -17 however is less for the present invent~on than for the process described above for F~g. 1 as will be clear from the following discussion.
D~luent-heavy hydrocarbon stream 17 at a temperature of about 210 to 215F
is pumped by pump 109 through l~ne 27 is cooled in heat exchanger 114 is .,.i:: . , . . . : .
~ 2~97~
, mixed with dlluent stream 22 and the comblned stream 23 flows into storage tank 112 at a temperature of about 90 to 110F. Mlxed stream 24 ls pumped by pump 113 through llne 26 and heat exchanger 114 where lt ls heated by lndlrect heat exchange w~th hot dlluent-heavy hydrocarbon stream 27 whlch ls s inltlally at a temperature of about 210 to 215F. The now-heated stream 28is contacted wlth carbon dloxide stream 30 between about 80 to 217F
preferably 95 to 166F and between 400 and 1200 pslg ln fluld-fluld contactor 115 where C~ dlssolves ~n the d~luent-heavy hydrocarbon mlxture to yield a reduced-vlscosity stream 31 conta~nlng heavy hydrocarbons dlluentj and C~ whlch flows to a plpeline for transportatlon to a reflnery. Undlssolved gas flows from contactor 115 via 11ne 29.
Optlonally the heavy hydrocarbon-dlluent-C~ mlxture is cooled to about 40 to 100F by flowing through line 32 cooler 116 and llne 33 to the plpeline for transportatlon to a reflnery. The stream typlcally contalns 0-1 to 0.3 volumes of dlluent and 5 to 8 lbs. of C~ per unlt vclume of the origlnal heavy hydrocarbonsj to g~ve a typ~cal k~nematlc viscoslty of less than 250 centlstokes. Other diluent-C~-heavy hydrocarbon ratlos can be used depending on the type of heavy hydrocarbons season of the year and other factors.
EXAMPLE
The process performance of the present ~nvent~on ls compared with existlng process technology ~n the followlng example.
Uslng exlstlng technology sùch as that d~sclosed ln prevlously-clted art'cle by R. R. Capellng bltumen at 7 000 bb1/day ls mlxed with 3 850 bbl/day of condensate diluent to y~eld a b~tumen-dlluent mlxture of 10 850 bbl/day having a k~nematic v~scos~ty of about 175 centlstokes at 55F. Thls bltumen-dlluent mixture ls prepared and sent to a plpellne as ; lllustrated ln Fl;g. 1. For th~s example an 8-lnch pipeline having a length of 100 miles ls assumed~for transport~ng the b~tumen-d~luent mlxture and a 4-lnch plpellne having the same length ls assumed ~or transporting the dlluent from lts source to the blending process site. The bitumen-dlluent mlxture ls pumped to the pipeline at 870 ps~g by transfer pump 113 of Flg. 1 and pumped through the 100-mile p~pel~ne by a number of pumps spaced ,~
g along the length of the p~peline. D~luent ~s pumped from its source to the blending process site by a series of pumps spaced along the 100-mile pipe-line. The net pumping horsepower requlred for the transfer pump product pipeline pumps and d~luent p~pel~ne pumps for th~s example ~s summar1zed ~n Table 1.
In the appl~cation of the present invention as shown ~n Fig. 2 7 000 bbl/day of bltumen ls mlxed wlth 1 540 bbl/day of condensate dlluent and the m~xture 26 ls heated to 95F by ~nd~rect heat exchange with hot bltumen-diluent stream 27 ~n heat exchanger 114. The heated mlxture 28 ls contacted with C~ at about 870 pslg ~n flu~d-flu~d contactor 115 to d~ssolve about 1 335 000 SCFD of C~ in the m~xture. The bitumen-diluent-C~ mixture at about 870 ps~g and 95F flows through l~ne 31 at a rate of 9 240 bbl/day to the pipellne in which the mixture cools to pipel~ne temperature during transportation to a refinery. Optionally the mixture passes through line 32 to cooler 116 where ~t ~s cooled to about 40 to 55F pr1Or to flowing to the p~pel~ne through line 33. The net pumping horsepower for the present invent~on is summarized and compared with the ex1st~ng process ln Table 1.
- :'-, ~
. .: .
: : .
~-- 2~7~
.
Comparison of Existing Process With Present Invention Existing Present Process Invention -:(Fig. 1) ~F~g. 2) Bltumen Flow, bbl/day ~7,000 7,000 Diluent Flow, bbl/day 3,850 1,540 02 required, MSCFD -- 1,335 Total flow to pipeline, bbllday 10,850 9,240 V~scoslty at 55F, centistokes 175 175 Pump1ng requlrements, BHP
Transfer pump 486 414 P~peline product pumps 1,120 816 Plpellne diluent pumps 360 36 Total : 1,966 1,266 ~;: 20 By utlllzlng the process of the present ~nvention, as ~llustrated by this example, an equ~valent amount of b~tumen can be transported at equ~val~nt plpel~ne cond1t~ons with a d~luent requ~rement 60% lower than ~25 that of the exlst~ng process. Th~s advantage of reduced d~luent requ~rement :wlll become more ~mportant as d~luent avallab~ y decreases and dlluent cost increases ~n future years. The example also illustrates that by utllizing the present ~nvent~on, the total volume of flu~d which must be pumped to transport a unlt volume of bitumen or other heavy hydrocarbons is decreased, thus decreaslng the pumping costs for a given mixture viscosity, p~pel~ne dlameter, and p~pel~ne length. In the example, the total mixture volume requ~red in the present invent~on ~s 15% less than that of the existing process, which reduces the total pump horsepower by 36%. The overall economic advantage of the present invention wlll depend on a number - 2~ ~71~
of factors including bitumen or heavy hydrocarbon properties diluent cost C~ cost power cost and the s~ze and length of product and dlluent pipelines.
Bitumen and heavy oil are often produced from hydrocarbon-bearing formations or reservo~rs by thermal recovery methods includ~ng in situ combust~on talso known as f~reflood~ng) and steam ~njection ~also known as steam flooding). In both cases the heat from in situ combustion or steam injection reduces the v~scos~ty of the heavy hydrocarbons in the reservoir thereby caus~ng flow toward producer wells from which the heavy hydrocarbons are produced.
In the in s~tu combust~on process the heavy hydrocarbons are ignited at the bottom of an ~njection well and an oxygen-contain~ng gas is ~njected to sustain combust~on. The heat and product gases from the combustion cause the heavy hydrocarbons to flow to adjacent product~on wells from which heavy hydrocarbons and combustion gases are produced. The heavy hydro-carbons are then treated and m~xed w~th d~luent as earl~er described for transportation by p~pel~ne. The combust~on gases from this process conta~n light hydrocarbons steam carbon d~ox~de and other components. Carbon d~oxide ~s recovered from th~s combustlon gas for ~ntroduction into the heavy hydrocarbon-diluent mixture for further viscosity reduction as d~sclosed in the present ~nvent~on. There are a number of known methods for recover~ng C~ from such a combust~on gas and these include for example chem~cal react~on w~th amine-based solvent solut~ons physical d~ssolution under pressure by methanol or ether-based solvents or phys~cal adsorption processes. For cases in which the 'n s~tu recovery process uses pure oxygen for combust~on the produeed combustlon gas may be su~f~ciently h~gh ~n C~
content to be used directly in contactor 115 of Fig. 2.
In the steam inject~on method steam ~s produced ~n boilers by the combustion of natural gas produced gas or other hydrocarbon fuels and is in~ected into the reservoir which heats the heavy hydrocarbons such that they flow to adjacent product~on wells from wh~ch heavy hydrocarbons and product gases are recovered. In an alternate mode of operat~on steam is injected into a format~on through an injector well for a specified perlod of time. At the end of th~s period steam injection is discont~nued and heavy 2Q~ 9~
hydrocarbons flow into this well and are recovered. In the present ~nven-tion, carbon dioxide is recovered from the combustlon flue gases from the steam boilers for introduction into the heavy hydrocarbon-dlluent mixture for further viscosity reducti:on. C~ can be recovered from the steam boller combustion flue gases by means of the known processes described above.
Thus the process of the present invent~on can be integrated with eithsr of these two thermal methods of produc~ng heavy hydrocarbons by recoverlng the required carbon diox~de from the byproduct combustlon gases produced ~n these thermal production methods. As discussed earlier, th~s recovered C~
is ~ntroduced ~nto the heavy hydrocarbon-d~luent m~xtures under controlled condlt~ons such that no C~ is present as a gas while the heavy hydrocarbon-d~luent-C~ m~xture flows through the p1peline.
Whlle carbon dioxide is preferred for use in the present invent~on, other components wh~ch are gaseous at amb~ent pressure and temperature can be used. These ~nclude methane, ethane, propane, butane, and other low-boillng components wh~ch are present for example in the gases produced w~th the heavy hydrocarbon product ~n the two recovery methods d~scussed above, or are present ~n natural gas. M~xtures of carbon diox~de w~th these other components can also be used as the misc~ble flu~d of the present ~nventlon.
Claims (16)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for reducing the viscosity of a heavy hydrocarbon product which at ambient conditions exhibits a fluid viscosity sufficiently high to render pipeline transportation infeasible, said process comprising the steps of:
(a) mixing said heavy hydrocarbon product at a super-ambient temperature with a first amount of hydrocarbon diluent;
(b) separating water and noncondensible gas from said mixture of heavy hydrocarbon product and hydrocarbon diluent to yield a first diluted heavy hydrocarbon product;
(c) cooling said first diluted heavy hydrocarbon product and mixing it with a second amount of hydrocarbon diluent to yield a second diluted heavy hydrocarbon product; and (d) heating said second diluted heavy hydrocarbon product and contacting it with a miscible fluid whereby at least a portion of said miscible fluid dissolves in said second diluted heavy hydrocarbon product;
thereby producing a reduced-viscosity mixture suitable for pipeline transportation.
(a) mixing said heavy hydrocarbon product at a super-ambient temperature with a first amount of hydrocarbon diluent;
(b) separating water and noncondensible gas from said mixture of heavy hydrocarbon product and hydrocarbon diluent to yield a first diluted heavy hydrocarbon product;
(c) cooling said first diluted heavy hydrocarbon product and mixing it with a second amount of hydrocarbon diluent to yield a second diluted heavy hydrocarbon product; and (d) heating said second diluted heavy hydrocarbon product and contacting it with a miscible fluid whereby at least a portion of said miscible fluid dissolves in said second diluted heavy hydrocarbon product;
thereby producing a reduced-viscosity mixture suitable for pipeline transportation.
2. The process of Claim 1 wherein said miscible fluid comprises carbon dioxide.
3. The process of Claim 1 wherein said heavy hydrocarbon product is characterized as heavy crude oil with a gravity between about 12° and 17°API.
4. The process of Claim 1 wherein said heavy hydrocarbon product is characterized as bitumen with a gravity between about 8° and 12°API.
5. The process as recited in Claim 1 wherein said diluent is selected from the group consisting of gas field condensate, naphtha, light crude oil, light hydrocarbon fractions separated from topped crude oil, and mixtures thereof.
6. The process of Claim 1 further comprising the transporting of said reduced-viscosity mixture by pumping said mixture through a pipeline from a first point to a second point wherein said reduced-viscosity mixture is prepared at conditions such that none of said miscible fluid exists as a gas in said pipeline between said first point and said second point.
7. The process of Claim 6 wherein said second diluted heavy hydrocarbon product is heated to a temperature of between about 80°F and 217°Fprior to said contacting with said miscible fluid.
8. The process of Claim 6 wherein said second diluted heavy hydrocarbon product is contacted with said miscible fluid at a pressure between about 400 and 1200 psig.
9. The process of Claim 7 wherein said second diluted heavy hydrocarbon product is heated by indirect heat exchange with said first diluted heavy hydrocarbon product which is initially at a temperature between about 210° and 215°F.
10. The process of Claim 6 wherein the maximum temperature in said pipeline is less than the temperature at which said reduced-viscosity mixture is prepared.
11. The process of Claim 7 further comprising the cooling of said reduced-viscosity mixture to between about 40° and 55°F prior to flow into said pipeline.
12. The process of Claim 1 wherein said heavy hydrocarbon product is recovered from a hydrocarbon-bearing underground formation by a thermal recovery method.
13. The process of Claim 12 wherein said thermal recovery method is in situ combustion in which an oxygen-containing gas is injected into said formation to support combustion therein of a portion of said heavy hydrocarbon product and wherein another portion of said heavy hydrocarbon product is withdrawn at a super-ambient temperature from said formation along with a produced gas containing hydrocarbons and carbon dioxide.
14. The process of Claim 13 wherein a portion of said carbon dioxide is recovered from said produced gas and is used as said miscible fluid for contact with said heated second diluted heavy hydrocarbon product.
15. The process of Claim 12 wherein said thermal recovery method is steam flooding in which steam is generated by combustion of a hydrocarbon fuel in a boiler and is injected into said formation whereby said formation is heated and said heavy hydrocarbon product is withdrawn therefrom.
16. The process of Claim 15 wherein a portion of said carbon dioxide is recovered from flue gas produced in said combustion of hydrocarbon fuel and is used as said miscible fluid for contact with said heated second diluted heavy hydrocarbon product.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US37510989A | 1989-06-30 | 1989-06-30 | |
| US375109 | 1989-06-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2019760A1 true CA2019760A1 (en) | 1990-12-31 |
Family
ID=23479531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002019760A Abandoned CA2019760A1 (en) | 1989-06-30 | 1990-06-25 | Pipeline transportation of heavy hydrocarbons |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2019760A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2447356C2 (en) * | 2007-04-25 | 2012-04-10 | Тоталь Рафинаж Маркетинг | Method to feed fuel to plant for production of heavy crude oil, method to produce heavy crude oil and appropriate plant for production of heavy crude oil |
| WO2014152293A1 (en) * | 2013-03-15 | 2014-09-25 | Saudi Arabian Oil Company | System and process for handling heavy oil residue |
| WO2015024540A1 (en) * | 2013-08-22 | 2015-02-26 | Ulrich Wagner | Method for improving the transportability of heavy crude oil |
| US10240101B2 (en) | 2013-03-15 | 2019-03-26 | Saudi Arabian Oil Company | Process for combustion of heavy oil residue |
| CN110220119A (en) * | 2019-06-04 | 2019-09-10 | 黑龙江兰德超声科技股份有限公司 | A kind of oil country tubular good viscosity-falling unit |
-
1990
- 1990-06-25 CA CA002019760A patent/CA2019760A1/en not_active Abandoned
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2447356C2 (en) * | 2007-04-25 | 2012-04-10 | Тоталь Рафинаж Маркетинг | Method to feed fuel to plant for production of heavy crude oil, method to produce heavy crude oil and appropriate plant for production of heavy crude oil |
| WO2014152293A1 (en) * | 2013-03-15 | 2014-09-25 | Saudi Arabian Oil Company | System and process for handling heavy oil residue |
| US10240101B2 (en) | 2013-03-15 | 2019-03-26 | Saudi Arabian Oil Company | Process for combustion of heavy oil residue |
| WO2015024540A1 (en) * | 2013-08-22 | 2015-02-26 | Ulrich Wagner | Method for improving the transportability of heavy crude oil |
| CN110220119A (en) * | 2019-06-04 | 2019-09-10 | 黑龙江兰德超声科技股份有限公司 | A kind of oil country tubular good viscosity-falling unit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102159675B (en) | By hot pressure (hydraulic) water and fluid recovered by the method for whole crude upgrading | |
| EP2220338B1 (en) | Method of injecting carbon dioxide | |
| US8261831B2 (en) | Apparatus and methods for the recovery of hydrocarbonaceous and additional products from oil/tar sands | |
| CA2693640C (en) | Solvent separation in a solvent-dominated recovery process | |
| BRPI0607426B1 (en) | integrated process to transport and process heavy oil or bitumen | |
| US10041340B2 (en) | Recovery from a hydrocarbon reservoir by conducting an exothermic reaction to produce a solvent and injecting the solvent into a hydrocarbon reservoir | |
| CA2962274C (en) | Methods and apparatuses for obtaining a heavy oil product from a mixture | |
| CA2019760A1 (en) | Pipeline transportation of heavy hydrocarbons | |
| CA2803985C (en) | In situ combustion process with reduced co2 emissions | |
| US11078767B2 (en) | Apparatus and method for potable water extraction from saline aquifers | |
| US8528645B2 (en) | Systems and methods for producing oil and/or gas | |
| US8991491B2 (en) | Increasing enhanced oil recovery value from waste gas | |
| CN102325962A (en) | Systems and methods for producing oil and/or gas | |
| CA3026716C (en) | Processing of produced fluids from a subterannean formation in a near-azeotropic injection process | |
| US20240011376A1 (en) | Method for recovering hydrocarbons with an organic solvent injection blend | |
| SHAH | Transformation of energy, technologies in purification and end use of shale gas | |
| US20230151719A1 (en) | System and Method for Enhanced Petroleum Product Recovery | |
| CA3186453A1 (en) | Systems and methods for processing fluids for recovery of viscous hydrocarbons from a subterranean formation by a cyclic solvent process | |
| Shokoya et al. | Effect of CO2 concentration on oil recovery in enriched flue gas flood | |
| Kristanto et al. | Improvement in Oil Recovery by Water Driven Miscible CO2 Slug Flooding | |
| Rehman | A techno-economical evaluation of miscible flooding. | |
| BRPI0502506B1 (en) | Process of obtaining on-site solvents and their use in artificially raised oil production processes |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19921225 |