This document summarizes a paper about flumping, a combination of flowing and pumping where a pumped well also flows from the casing-tubing annulus. The paper presents a methodology to calculate the bottom pressure and gas-oil ratio conditions needed to achieve flumping. It applies the methodology to example well data, presenting production rates and efficiencies for different bottom pressures. The results show that flumping can optimize production by allowing simultaneous pumping and annular flow.

1. Copyright 2001, Society of Petroleum Engineers Inc.
This paper was prepared for presentation at the SPE Latin American and Caribbean
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Abstract
The inflow performance of a well represents the ability
of that well to give up fluids. This ability depends to a
great extent upon the type of reservoir and drive
mechanism, and such variables as reservoir pressure,
permeability, etc. It is common practice to assume that
inflow into a particular well with constant conditions is
directionally proportional to average reservoir
pressure. When this pressure decline, the well is not
able to flow by itself and it is necessary to used a
properly artificial lift method.
In many cases, sucker rod pumping is the method
used.
Some times, the dynamometer registers shows that
the well is flowing by itself and at the same time the
sucker rod beam is pumping, and as soon as the
operator stop de sucker rod beam, the production
quickly ceases till de sucker rod start again, but still
without any sign of pumping action.
But flumping is a combination of flowing and pumping,
and it is when a well that is being pumped through the
tubing is flowing at the same time from de casing
tubing annulus. There is no question here of a dual
completion, and both the annulus and the tubing
production come from the same horizon.
Many wells today are flumping, and this condition is
generally fortuitous and no conscious effort has been
made to bring it about. It is therefore worth inquiring
into the nature of flumping to be able the engineers
achieve a production method to be applied in certain
types of well.
This method used is to suppose the oil production, to
know the pump efficiency, calculate the production
curve in the annulus, and define the vertical flow
condition that may be possible the combination of
flowing by the annulus and pumping in the tubing
production.
Introduction
When the pressure of the oil reservoirs declines , they
change the flowing well performance, chord with the
flowing well´s behavior
Between the phases gas and liquids and considering
that it conforms the pressure constantly decreases in
their vertical lift for the production pipe, the raw
petroleum removes the gas that contains in solution,
falling the volume of liquid, modifying its relationship
with free gas, generating such flows quickly as that of
bubble, slug, froth, annular, and mist that together with
other such variables as viscosity and its dependence
of the pressure and temperature, characteristic PVT of
the fluids of the location, head pressures, etc., they
finish hopelessly in the necessity of establishing a
system of artificial production to optimize the
extraction of liquid of the oil wells.
One of the systems of artificial extraction used
historically, is the beam pumping.
Under this extraction system, some wells don't present
action of pumping before the surface dynamometer,
but however, they have a continuous production, in
many in disagreement cases with the bottom hole
design. On the other hand if we suppose that the well
returned to its fluent condition and we stop the team of
pumping, we observe that the contribution of liquid for
the production pipe decays immediately and alone it
returns when the action of the mechanicalpump
begins, it is worth to say, the well really flows
maintaining the valves it fixes and opened traveler, but
alone when the team of pumping is working. This way
of producing can be almost continuous, to last many
months or to appear intermittently, it is known in the oil
jargon as agitation.
SPE 69512
FLUMPING
Eduardo Braganza, Esteban González

2. 2 EDUARDO BRAGANZA, ESTEBAN GONZALEZ SPE 69512
In other circumstances that it is in fact the topic that
occupies us, the surface dynamometer it indicates that
the well production usually takes place for pumping
mechanic, but when observing the annulus, or rather,
to verify their operative condition, we find that the well
is arising. This fluent situation with pumping in most of
the locations is fortuitous and some doesn't respond to
design and therefore, it is generally intermittent and
chord only at once in particular in those that the
conditions of bottom pressure and relationships gas
petroleum, among other variables, allow the annulus
fluency.
The work reason is to normalize a calculation that
allows ahead of time, to design a bottom installation
jointly for mechanical pumping with the conditions of
necessary annulus to maintain a fluency with
pumping.
Development
When analyzing the effectiveness of the bomb in the
inferior part of the well, it is normal to calculate the
defined volumetric efficiency as the production of
liquid pumped from the well, referred to the
displacement of the bomb under the conditions of well
bottom.
If it is considered that the volume of liquid produced, it
is the one displaced by the bomb, you can calculate
the efficiency of the anchor of gas
Eg =
AiRsGORiq
DiBiqqwiAiRsGORiq
*)(
**)(
−
−++−
!
!!!
being D the displacement of the bomb to produce the
liquid q i +qwi + the gas not derived to the annulus,
taken place by the location for a pressure of bottom
pwfi, with a relationship gas-petroleum (GOR) and Rs
(dissolved gas to Pwf)..
It will be considered that the production of the well
responds to IPR direct line.
Being
Ai =
614,5**
***
Tapwfi
ZiTwfipa
With reference to the relationship gas petroleum, it is
remembered that when a well is extracted by pumping
mechanic, they decrease the bottom pressures to
values inferior limits, and you can consider that the
relationship instantaneous GOR will depend
exclusively on this pressure and it will maintain low
and constant values, whenever we operate in a
location with gas drive solution, like it is that of this
presentation.
The effectiveness of the anchor of gas, is expressed
as the efficiency Eg, that indicates the proportion of
gas free present that strays for the annulus. This
proportion of splits gas will allow us to study the
fluency in the ring space.
The bottom temperature will stay constant.
Knowing the flow taken place to a given bottom
pressure, the GOR, and the efficiency of the anchor of
gas, the volume of gas is calculated derived to the
annulus space.
Knowing the gas that goes for the bomb and the
quantity of liquid taken place by the well, according to
the IPR, it is defined the flow of liquid derived to
among pipes and for each bottom pressure the
relationship liquid gas that has in the ring space.
The production of liquid is obtained by annulus space,
starting from the total production of petroleum and
gas, for each bottom pressure, subtracting the
mechanical displacement of the bomb and the gas not
derived to the ring space.
The resulting GOR is determined for each pwf.
Then, fixed the flow to extract for among columns,
they are defined, using Gilbert or Hagendorn and
Brown, to the depth of the formation, the bottom
pressures and necessary GOR to achieve the fluency
for the ring space. The intersection of the calculated
resulting GOR, Chart 1, curve 1, with the necessary
ones to achieve the fluency, chart 1, curve 2, define
the bottom pressure that will take place for pumping in
the production pipe and simultaneously for fluency in
the ring space..
The methodology will be developed explained with the
data of a well designed to achieve flumping.
Results
Flumping
AIB LUFKIN-M-456D-305-144
Stroke 120”
G.P.M. 7
Rod string Nro 85 -
29,6% 1" 30,4% 7/8" 29,5% ¾ " 10,5% 5/8"
Production pipe - diameter 2 7/8"
Casing-diameter-5 ½"
Tubing Shoe 1981 m
Crossbeam 2010 m
Wellbore Fund 2048 m
Perforation 1936-1983 m
Production rate 26 m3/día
WOR 63 %
Associate gas 1385 m3/día
Pwf 44 kg/cm2
Half pressure or static 129 Kg/cm2
Specific graveness 0,865
Gas Anchor :poor man anchor.
Tubing inside diameter 1,75 “
Calculations:
Table 1, Table 2, Table 3, Chart 1

3. SPE 69512 FLUMPING 3
Eg chart 2
Tubing Production = 128 bbl/day
Casing Production = 16,5 bbl/day
Bottom pressure = 792 psi
GOR (annulus)= 0,744 mcft/bbl
Conclusions
This work has been developed with the certainty that
the sucker road pumping has been considered a lot of
time like a mechanism of fundamentally simple
pumping and understood by all. This demonstrates it
maybe the real achievements in the design of
mechanical systems that operates with efficiency in
situations that demand every time bigger depth of the
well or deviation of the hole, in those that one has
bigger production of sand or paraffin, or with raw with
bigger or smaller viscosity, significant quantities of
free gas, etc.
On the other hand the wells to pumping are not
generally spectacular wells, their productions don't
always call to concern to the extraction engineers
neither the interests managerial positions but in new
wells and of potentials high.
It is for this reason and without forgetting that the
mechanical pumping this in the heart of this industry,
is expected that the exhibition of this work stimulates
an interest renovated in some of the queries and
possibilities that remain with a partial solutions or
without answers.
A method to improve the efficiency of the bomb is to
split the free gas up in the ring space of the well in
question and to purge this gas in the casing head
valve, through individual or for the same conduction
line that takes the petroleum taken place by the tubing
production to the respective battery.
The free gas can also be used to give energy motor.
Nevertheless always this situation is of conflict and a
permanent problem in the mechanical pumping, is the
annulus free gas .
No producer doubts that occasionally he/she has
observed fluency in well head tubing pipe.
Therefore, to be able to design an installation of
pumping considering fluency at the same time with the
action of the bomb. It constitutes an effective method
of producing and optimizing. It is added charts and
tables of results to help the calculates.
Nomenclature
D = bomb displacement, bbl/day
q0 = Oil production in std conditions, bbl/day
qw = Water production in std conditions, bbl/day
GOR = relationship gas petroleum, ft
3
/bbl
pa = atmospheric pressure, psi
pwf = bottom pressure, psi
ps = static pressure, psi
Eg = gas anchor efficiency
Ar = sucker road cross-sectional area, sq inch
M= crank/pitman relation
Sp = Plunger stroke, inch
T1 = Temperature of bottom of the well, ºF
T a= standard Temperature, ºF
qg = gas rate, ft
3
/day
Bo = Petroleum volume factor
sgo = oil specific graveness
sgg = gas specific graveness
Subscripts
i= Bottom hole condition
Acknowledgments
We thank, Pecom Energía, Entre Lomas for valuable
experimental information.
References
- Kermit E. Brown, the technology of artificial lift
methods copyright 1984,
- Penn Well Books, Pennwell Publishing Company,
Tulsa, Oklahoma
-T.E.W.Nind, Foundations of Production and
Maintenance of Oil Wells". First Edition 1987, Editorial
Limusa, Mexico.
- Francis S. Manning and Richard E.Thompson, Oil
Field Processing of petroleum, volume 2. Crude Oil",
Copyright 1991, Penn Well Books, Pennwell
Publishing Company, Tulsa, Oklahoma

4. 4 EDUARDO BRAGANZA, ESTEBAN GONZALEZ SPE 69512
TABLE 1
S (inch)= 120 GLR (cft/bbl) 299 c/h = 0,29
H (ft) = 6500 GOR (cft/bbl) 808 Ar (sq inch) 0,5907
IP(bbl/psi) = 0,131 sgo= 0,834 Wf (lb) = 5650
Ps (psi) 1896 sggs= 0,7 Wr (lb/ft) 0 14203
TF (ºF) = 158 ºAPI = 38 Er (inch/lb ft)= 7,38E-07
Sp (inch) = 98,8 N (stroke/min) = 7 K (% g) = 0,357
D (bbl/day) = 247,0 Dplunger (inch) = 1,75
TABLE 2
Pressure (psi) ql (bbl/day) qo*Bo qw qg(free to pwf) q (total to pwf) Eg
900 130,5 49,6 82 83 214 0,00
850 137,0 52,0 86 95 233 0,15
800 143,6 54,4 90 109 254 0,32
750 150,1 56,8 95 126 277 0,46
700 156,7 59,2 99 145 303 0,58
650 163,2 61,5 103 168 332 0,67
600 169,8 63,9 107 195 366 0,75
550 176,3 66,3 111 227 404 0,81
500 182,9 68,6 115 266 449 0,87
450 189,4 71,0 119 313 504 0,91
400 196,0 73,3 123 373 570 0,94
350 202,5 75,6 128 451 655 0,96
300 209,1 78,0 132 556 766 0,98
250 215,6 80,3 136 704 920 1,00
200 222,2 82,6 140 928 1150 1,00
TABLE 3
Curve 1 Curve 2
qg (bomb) q gas (annulus) q liq (annulus) Pwf GLR (annulus) Pwf GLR
83 0 0,0 900 0 2920 0
81 14 0,0 850 0 2520 0,1
75 35 16,5 800 0,65 2360 0,2
68 58 16,5 750 1,00 1920 0,3
62 84 16,5 700 1,34 1600 0,4
55 113 16,5 650 1,65 1280 0,5
49 146 16,5 600 1,96 1020 0,6
42 185 16,5 550 2,24 760 0,8
36 230 16,5 500 2,52 720 1
29 284 16,5 450 2,78 690 1,2
23 351 16,5 400 3,03 670 1,5
16 435 16,5 350 3,26 620 2
10 546 16,4 300 3,48 590 3
3 701 16,4 250 3,69 560 5
0 928 16,4 200 3,88 520 10

5. SPE 69512 FLUMPING 5
Chart 1
Cas ing flow ing bottom hole pre s s ure
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
0 500 1000 1500 2000 2500 3000 3500
Pressure (psi)
GLR(mcft/bbl)
Curve 2
Curve 1
Chart 2
Anchor gas e fficie ncy
0,30
0,40
0,50
0,60
0,70
0,80
0,90
1,00
1,10
100200300400500600700800900
Pressure (psi)
Eg