Note: Descriptions are shown in the official language in which they were submitted.
~0~ 27~2
Trit' presen t lnVen t. ion reld ~:e!~ c3 0 i 1, Wa-ter and Gas
Separdtors.
BACKG~OUND OF T~E INV NTION
In the pe-troleum industry, oil wells produce gas
together with an elllUl~iOrl of water and oil. Separators
are used -to firstly, separate the yas, arld secorldly,
separate the oil and water comporlerlts of -the emulsion.
Irlitially these separa-toLs were operl vesse:ls
divided into zones. The yas was discharged to the
atmosp~lere. T~le water would se-t-tle out and be withdrawrl
from the bottom of the vess~l. The petroleum would
float on the water and be withdrawrl from the top of t~le
15 vessel. These separators were consideIed inefficien-t as
the gravita-tional settlirly procedures were 810w
resulting in reduced flow rates.
Separa-tors presen-tly irl use are pressure vessels
20 whic}l are maintained at between 25 and 35 pounds of
pressure. Hea-t is applied to accelera-te the separa-tion
of the water and the oil. As gas separa-tes from the
emulsion, the gas is vented -to a flare, where it is
burned. As the oil is separated it iS pumped iLltO
25 storage tarlks. The flow rate is maintairled thro-ugh -the
pressure in the pressure vessel. Throuyh prolonged use
it has been determirled -that treating the emul~iorl under
pressure al50 has disadvarlta0esO When the emulsion is
treated under pressure some gas unavoidably remairls ir
30 the oil. When oil is pumped from the separator, where
it is under 25 -to 35 pounds pIessure, to a storage -tank,
at atmospheric pre~sure, gas is released in what is
termed a "vapour flash". This "vapouI flash" poses a
potential danger to the enviror~merlt and to the health
35 and safety of workers
20127~2
SUMMARY OF THE IN ENTION
What is a method of elimirlatirly the darlyer posed by
"vapour fla~h" ln Oil, Water and Gas Separators.
Accord.iny to one aspect of tsle present invention
-tslere is providec~ a metslod of reducirlg the danyer of
vapour flash in Oil, Water and Gas Separators. The
method is comprised of the following described steps.
Place a secondary pressure vessel having an iniet, an
10 outle-t, gas separation means and gas ventiIly means,
inside of a sleated primary pressure vessel having an
inlet, means for se~araLiosl of oil and water, a wa-ter
outlet, an oil outlet and means for ventiny gases. The
outle-t of the secondary vessel is conrlected to tsle inlet
15 of the primaLy vessel. Flow oil well production,
contairlirlg gas toyether ~itsl an emulsion of oil and
water, through the secorldary vessel at pressures of
between 10 and 60 pounds, tslereby substantially
degasifying the resultirlg oil and water emulsion which
20 flows througsl tsle ou-tlet of the secondary vessel into
tsle inlet of the primary vessel. Separate the oil and
water in tsle primary vessel at sub~-tarl-tially atmospheric
pressure, such that any yases remaîning in the oil are
released in-to the primary vessel for ventirly -througsl the
25 gas venting means to an external flare.
According to arlo-ther aspec-t of the inverl-t.iorl tslere
is provided an Oil, Water, and Ga~ Separa-toI WsliCsl is
30 comprised of a primary pressure vessel hclvisl9 a top, a
bottom, a first end and an second end. Tsle lonyitudirlal
ax.is of -the primary vessel ex-terlds subs-tan-tially
horizontally. A bafrle extends substantially ver-tically
from tsle bo-t-tom of -the primary vessel intermediate the
~127~2
~ d a~ rl~ ~r~ U~ lclt ~le primary
ves~el is divided into a first sectiorl and a second
sect:iorl. Liquid~ in t~le firs-t sectioll mu~-t flow over
the baffle to ent:er tne second sectiorl. The primary
vessel ha~ a fluid inlet in -the fir~t sectiorl, a liquid
outlet adjacent the bottom of the first sectiorl whereby
water is drained, a liquid outlet adjacen-t the bo-t-tom of
the secorld section whereby oil is drained, and a gas
ou-tlet adjacent the top of one of -the sectiorls whereby
10 ~as i9 vented to an external flare~ Mearls is provided
for heatirly the firs-t sectiorl of the primary vessel. A
secondary pressure vessel iY mourlted within the first
section of the primary vessel. The secondary ve~sel has
a fluid inlet whereby productiorl from an oil well can be
15 received from an ex-terrlal source, gas separation mean6,
a gas outlet whereby gas is vented to an external rlare,
and a f luid outlet which is connec-ted to -the fluid inlet
of the primary vessel.
The Applicants determined tha-t, con-trary -to
conventional thinkirlg, the entire separa-tor unit rleed
not be maintairled under pressure. Placing a secondary
pressure vessel within the primary vessel enables them
to separa-te the oil and water at substantially
25 atmospheric pressure. The Applicarlt recommends that
approximately 4 o~. of pressure be maintairled to prevent
air from entering the separator. Treatment at
substarltially atmospheric pressure eliminates the danger
of vapour flash.
The Applicarlt~ ~escIibe~ method alld apparatus alYo
makes the separation of oil and wa-ter more efficient.
The higher the pressure in the primary vessel -the more
heat must be applied to proJIlote separatiorl of -the oil
35 and water. By operatirlg -the primary vessel a-t
23~127~2
'`;Ub:;larlt.ial ;y dtmO~;yller'iC: pl''eSSllre, tile ApE~licanls
re~uire less ~ledl .
Tlle Applica~lts decic:~it)ed met~lod arla apparatus also
provides advasltayes irl relatiorl to safety and
envirorlmerltal ~ro-tec:-ior~ the yas ven-tirlg in
conventiorlal sepaLatorY becomes plugged the pre~sure in
-the separator wil~ build until the yas must be released
direc-tly into the atmosphere throuyh a safety release
10 valve or there will be an explosior1. The Applicants
have yas ventirlg means connected to a flare in both tne
primary vessel and the secondary vessel vir-tually
eliminating the ri.sk of releasing gas directly irl-to the
atmosphere. If a separator ruptures it preseI1-ts an
15 immediate and grave environmental hazard~ Wi-th -the
Applicant's method -the vessel under pressure, the
secondary vessel, is completely contained within the
primary vessel should a rupture occur.
The Appl.icants described method and apparatus also
provide6 more versa-tili-ty for po-ten-tial use in tHe
field. The Applicarlts can have oil withdrawn from their
primary vessel for haulir1cJ by a tank -tr-uck, without
ha~ard. Oil can also be pumped directly from a -tank
25 truck irlto the primary v~ssel, as the pump from -the -tank
truck must merely overcome atmospheric pressure. Of
course, -the need for a varie-ty of accessory equipment,
such as "gas boots" previously required for safety
reasons has been elimina-ted.
BRIEF DESCRIPTION OF THE DRAWINGS
These alld other features of -the inverltiorl wlll
become more apparent from -the followiny descrip-tion in
which reference is made -to the appended dIawirlgs,
35 whereir1:
20127~2
FIGURE 1 i~; d .ic:~lem~l.i(. reçJrf.~ierltatiwrl of a
preferred embo~liment oi the in~erltiorl.
DETAILED D~SCRIPTION OF THE PREPERRED EMBODIMENT
T~le preferred e~nbudime}lt, generally designated by
reference numeral 10, is an Oil, Water and Gas Separator
for use irl the petroleum indu~-try. T~le Applicants
determirled that, contrary to corlverl-tional thi-lkirlg, the
entire separator ur~i-t need not be maintained under
10 pressure. They placed a ~econdary pressure vessel 12
within a primary ve~sel 14. This enabled them to
separate the oil and water at ~ubstantially atmosprleric
pressure arld provided a number of di~tirlc-t advarltayes.
The prefer~ed embodiment will now be clescribed Wit~
15 refererlce to FIGURE 1.
The priMary components of Oil, Water, and Gaa
Separator 10 ar the pri~ary pressure vessel 14 and
secondary pres~ure vessel 12 previously referred to.
20 Primary pressure vessel 14 has a top 16, a bot-to~n 18, a
first end 20 and an second end 22. The longitl1diIlal
axi~ ~not ~hown) of primary vessel 14 ex-tends
substantially horizoxltally. A baffle 24 e~tends
su-ostantially vertically from bottom 18 of primary
25 vessel 14 intermediate first end 20 and second erlcl 22.
Baffle 24 divides primary vessel into a first section 26
and a second section 28. Li~uids irl first sectiorl 26
mu~t flow over baffle 24 to enter second section 28.
Primary vessel 14 has a plurality of irllet~ and outlet~.
30 A fluid inlet 30 is positiorled in firs-t sectiorl 26. A
water outlet 31 is poYitiorled adjacerlt bottom 18 of
first section 26. An oil ou-tlet 32 is po~itioned
adjacerlt bottom 18 of secorld sectiorl 28. A gas ou-tlet
34 is positioned adjacent top 16 of section 26. A
35 heatirlg pipe 36 extends into first section 26 of primary
20~2~
vessel 14. The }leat to heatirly pipe 36 is generclted by
an exterrlal burrler 38 which is vented through exhaust
stack 40. Seconda}y pres~llre vessel 12 is moun-ted
withirl first sec-tion 26 of prilllary vessel 14. Secondary
vessel 12 hcls a plurality of inlets arld ou-lets. A
fluid inlet 42 i5 connected to a remo-te source (not
9hOW}I). A ga~ outle-t 44 is provided for venti}lg gas -to
an external flare (not shownj. A Eluid outlet 46 is
provided which i5 con}lected -to fluid inlet 30 of primary
10 vessel 14. Gas separation means 48 is provided withir
secondary vessel 12. Althouyh rlo-t illustrated, gas
separation means 48 consists vf a de~iector plate, and a
demister pad -to promo-te coalescerlce of liquids.
Attached to first erld 20 of primary vessel 14 is a
15 housing 50 containirly all necessary controls, gauges and
meters. A safety relief valve 52 is provided on primary
vessel 14 -to guard agains-t pressure buildup in -the event
that gas outlets 34 or 44 are inoperative.
The preferred me-thod will now be described Wi th
reference to Oil, Water, and Gas Separator 10 as
illus-trated in FIGURE 1. Flow oil well produc-tion,
containing yas together with an emulsion of oil and
water, -through a fully contairled secvndary vessel a-t
25 pressures of between 10 and 60 pounds. This serves to
substantially deyasifyiny the resultiny oil and water
emulsion which flows through the outlet of the secondary
vessel into the inlet oE -t~le primary vessel. In Oil,
Water, and Gas Separa-tor 10 oil well productioll enters
30 secondary vessel 12 through inle-t 42. Gas is separatr-d
by gas separatio}l means 48 arld vented out of gas outlet
44 -to a remo-tely located flare (no-t s}lowrl). T~le
resulting emulsion of water and oil flows from ou-tlet 46
oE secondary vessel 12 in-to irllet 30 of primary vessel
35 1~.
~127~2
Sepasdte the oil and water in t~le primary vessel at
~ubs-tantially atmQspheric pressure, such that any gases
remaini~lg ill the oil are released iIltO the primary
vessel for ventirlg through the gas venting mearls to an
ex-terrlal rlare. In Oil, Wa-ter, and Ga~ Separator 10 -the
emulsion of oil and water flowing in-to primary vessel 14
enters firs-t: section 2fi. First sectioII 26 is heated by
heatirly pipe 36. The heatirlg of tne emulsion promotes
and accelerates -t~le separa-tion of -the wa-ter and -the oil.
10 The oil floats upon -the wa-ter. As first sec-tiorl 26
begins -to fill, oil begirls -to spill over baffle 24 in-to
second sec-tion 28. Water is drained from primary vessel
14 -through water outle-t 31, provi~ed for the drainage of
liquids from first section 26. Oil is drained from
1~ primary vessel 14 through oil outle-t 32, provided for
the drainage of liquids from second section 28. As
emulsion flows from secorldary vessel 12 which is urlder
pressure, to primary -tank 14 which is at substantially
atmospheric pressure gas is released. Gas continues -to
20 be released as the emulsiorl as is heated by heating pipe
36 in first section 26. Such yas migrates to top 18 of
primary vessel 14, where it is vented thro-ugh ga~ outle-t
34 to an external flare. The Applicant prefers to
operate primary vessel 14 a-t approxima-tely 4 oz. of
25 pressure to ~void having external air enter pressure
vessel 14.
It will be apparerlt to one skilled in -the art tha-t
-the method and apparatus described eli~ninate~ the
30 problem of vapour flash whic.h exists in Oil, Water, arld
Gas Separators presently in use. It will also be
apparent to one skilled in -the ar-t tha-t -the method and
apparatus described provide a number of other
advantages, many of wh:ich have beerl previously
20~27~2
c1e~;oribed~ It will firlally be aE)parerlt -to one sl~illed
irl the ar-t that variatiorls may be made -to the preferred
emboclimerl t wi -t~lou c dep~r t irlg f rom the ~pix i t ar~d scope
Ol' the inverltion.
