EP0840836B1 - Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz - Google Patents

Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz Download PDF

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Publication number
EP0840836B1
EP0840836B1 EP96927604A EP96927604A EP0840836B1 EP 0840836 B1 EP0840836 B1 EP 0840836B1 EP 96927604 A EP96927604 A EP 96927604A EP 96927604 A EP96927604 A EP 96927604A EP 0840836 B1 EP0840836 B1 EP 0840836B1
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EP
European Patent Office
Prior art keywords
production
lift
gas
choke
control module
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.)
Expired - Lifetime
Application number
EP96927604A
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German (de)
English (en)
Other versions
EP0840836A1 (fr
Inventor
Wilhelmus Johannes Godefridus Josep Der Kinderen
Pieter Koornneef
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shell Internationale Research Maatschappij BV
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Shell Internationale Research Maatschappij BV
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Priority to EP96927604A priority Critical patent/EP0840836B1/fr
Publication of EP0840836A1 publication Critical patent/EP0840836A1/fr
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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
    • E21B43/121—Lifting well fluids
    • E21B43/122—Gas lift

Definitions

  • the invention relates to a system for controlling production of crude oil through a production tubing which extends into a gas-lifted oil well whereby lift-gas is injected at a downhole location.
  • the choke is located at the earth surface near the wellhead of the gas-lifted well.
  • the gas injection conduit which is usually formed by the annular space between the production tubing and the well casing, may have a length of several kilometres and may have such a large volume that it is not possible to accurately control the amount of lift-gas which is injected downhole into the production tubing by adjusting the flow of lift-gas that enters the lift-gas injection conduit via the variable choke at the wellhead.
  • Such a variable downhole orifice enables an accurate control of the amount of lift-gas into the well such that always a steady flow of lift-gas is injected and a stable and optimum gas-lift is created.
  • UK patent application GB 2252797 (which represents the closest prior art as referred to in the preamble of claim 1) discloses a gas-lifted oil production system wherein a production choke and an inlet valve in the gas injection conduit are adjusted simultaneously in a pre-programmed parametric logic sequence to improve the control of oil production.
  • a drawback of this known system is that said pre-programmed sequence generates a fixed regime for operating the two valves and which does not use feed-back of operating conditions to adjust said sequence.
  • the simultaneous adjustment of the two valves may lead to oscillations in the lift gas flow, particularly if lift gas stemming from a single source is injected into a plurality of wells.
  • the system according to the invention thereto comprises the control module comprising a PID controller which is set to dynamically control the opening of a choke in a production tubing in such a manner that the fluid pressure within said lift-gas injection conduit is minimized and stabilized.
  • a PID controller which is set to dynamically control the opening of a choke in a production tubing in such a manner that the fluid pressure within said lift-gas injection conduit is minimized and stabilized.
  • a PID controller is a controller which gives an output signal which is proportional to the input signal, but which also integrates and differentiates the input signal to adjust the characteristics of the output signal.
  • the control module may further comprise a master controller which incorporates a fuzzy logic algorithm to generate for the PID controller a setpoint for the pressure in the lift-gas injection conduit.
  • variable choke and control module are located at the earth surface at a location near the wellhead of the gas-lifted oil production well.
  • the location of the choke and control module at the earth surface allows installation and maintenance thereof outside the well and without interruption of oil production operations which saves significant cost and effort.
  • a gas-lifted crude oil production well comprising a variable choke 1 and a control module CM.
  • the choke 1 is mounted in a production tubing 2 which extends from near the bottom of an oil production well 3 through the wellhead 4 towards processing facilities (not shown) at the earth surface 5.
  • Oil is produced via perforations 6 that have been shot into an oil bearing formation.
  • a packer 7 is mounted near the lower end of the production tubing 2 which provides a fluid barrier between the inflow zone 8 at the bottom of the well and the annular space 9 that is formed between the outer surface of the production tubing 2 and the inner surface of a well casing 10.
  • lift-gas is injected via the annulus 9 and a downhole orifice 11 into the production tubing 2.
  • the lift-gas is fed into the annulus via a gas injection conduit 12 and an annular chamber 13 at the wellhead 4.
  • the gas injection conduit 12 is equipped with a choke 14 which serves to adjust the flow of lift-gas.
  • the considerable volume and length of the annular space 9 result in a significant delay between the moment at which the position of the choke 14 is varied and the moment that this results in a variation of the flow of gas that passes through the downhole orifice 11.
  • variable choke 1 and the control module CM serve to avoid that swift variations in the fluid pressure in the production tubing 2 would result in an unstable lift-gas injection regime whereby the lift-gas is injected in slugs via the downhole orifice 11 into the production tubing 2 and the well would start to produce irregular slugs of crude oil and lift-gas.
  • the control module CM is continuously or intermittently fed with data concerning the casing head pressure CHP measured by a pressure gauge at the top of the annular space 9 and the tubing head pressure THP measured by a pressure gauge at the top of the tubing 2. Also data are fed to the control module CM concerning the temperature T of the produced fluid mixture and the. flow of lift gas Q lg and of the produced fluid mixture Q prod measured by flowmeters that are mounted in the lift-gas injection conduit 12 and the production tubing 2, respectively. In the embodiment shown the control module CM does not only control the opening of the production choke 1, but also the opening of the lift-gas injection choke 14.
  • the principal operation of the control module CM is that it adjusts the opening of the production choke 1 such that the flow of lift-gas through the downhole orifice 11 remains approximately constant. This is achieved by maintaining a constant differential pressure across the downhole orifice.
  • the pressure downstream of the orifice can be influenced by varying the backpressure at the wellhead, i.e. the tubing head pressure THP. In this way the backpressure exerted by the tubing head pressure THP on the produced fluid mixture is varied such that the backpressure increases in response to a decrease in the measured casing head pressure CHP and vice versa.
  • This variation of the tubing head pressure THP is an adequate measure to accomplish a substantially constant rate of injection of lift-gas at the downhole orifice 11.
  • the control module CM aims to minimize the casing head pressure CHP by variation of the opening of the production choke 1.
  • control module CM is set to obey another rule which dictates that the lower the lift-gas injection rate Q lg is the wider the control margin Cm(t) on the production choke 1 needs to be. Setting this control margin Cm(t) requires some empirical judgement which is incorporated into a fuzzy control unit FCU which is described in more detail with reference to Fig. 2 and Fig. 3.
  • FIG. 2 there is shown a block-scheme which shows the operation of the control module CM.
  • the heart of the control module CM is formed by a conventional PID controller, in the block-scheme referred to as PID, which adjusts the position Cp(t) of the production choke 1 in response to variations of the measured casing head pressure CHP.
  • the flowscheme shows that the casing head pressure CHP is dependant of the tubing head pressure THP, the pressure P res of the fluid in the pores of the reservoir formation RES, and also on the lift-gas injection rate Q lg via the lift-gas choke 14 and the downhole orifice 11.
  • the fuzzy control unit FCU provides a casing head pressure setpoint CHP sp(t) for the PID controller and also adjusts the position of the lift-gas injection choke 14 on the basis of empirical data, represented by arrow 20, which identify classes of suitable positions of the chokes 1 and 11 for various production rates.
  • fuzzy control unit FCU acts as a master controller for the PID controller.
  • the first box at the top indicates that a control cycle starts with a measurement at a certain moment in time (t) of the lift-gas injection rate Q lg (t), the casing head pressure CHP(t) and the actual position Cp(t) of the production choke 1.
  • the next box indicates that on the basis of the measured gas flow rate Q lg (t) the fuzzy control unit calculates the choke margin Cm(t).
  • the fuzzy control unit FCU verifies whether the actual choke position Cp(t) is below the choke margin Cm(t).
  • fuzzy control unit FCU will decrease the setpoint for the casing head pressure CHPsp(t) for the PID controller, whereas if this is not the case said setpoint CHPsp(t) will be increased.
  • the PID controller subsequently verifies whether the measured casing head pressure CHP is lower than the setpoint CHPsp(t) supplied by the fuzzy control unit FCU.
  • the measurement and control cycle is then repeated after a selected interval of time and the same steps of the procedure set out in the flowscheme are taken again.
  • control module The performance of the control module was tested in a miniaturized well in which water was produced via an 18 metres high riser pipe and in which air was injected as lift-gas via an annulus surrounding the pipe to enhance the flow of water through the riser pipe.
  • the lift-gas injection rate Q lg was 15 m 3 per day and the productivity index PI, simulated with a variable restriction, was 10 m 3 per day per bar.
  • the graph shown in Fig. 4 shows the response of the casing head pressure CHP and fluid production rate Q prod to various settings of the production choke at the top of the riser pipe.
  • the horizontal axis of the graph represents elapsed time, in seconds.
  • the vertical axis contains a scale of 0-100 units which represent both the opening Cp of the production choke (in %), the measured casing head pressure CHP times a factor 50 (in bar) and the fluid production rate Q prod times a factor 10 (in m 3 per day).
  • the graph shows that at this choke setting the production rate Q prod was stable and averaged 1.9 m 3 /day.
  • power for actuating the production choke could be generated by a positive displacement motor or other rotary power generator which utilizes the elevated pressure of the lift-gas within the lift-gas injection conduit as a power source.
  • the inlet of the motor or generator is connected to the lift-gas conduit and the outlet thereof to the oil production tubing.
  • the control system according to the invention is also suitable for use on a well which comprises a plurality of crude oil production tubings which produce crude oil from various locations in a reservoir.
  • a well with multiple completions may produce crude oil either from various inflow regions along a single wellbore or from various inflow regions along different downhole branches.
  • various production tubings may be arranged concentrically within the upper part of the well and lift-gas may be injected at different depths into the production tubings via the annular space formed between the outermost tubing and the well casing.
  • each production tubing is provided with a control system according to the invention which adjusts the opening of a production choke near the top of the production tubing in question in the manner described with reference to the drawings then a stable gas injection and an optimum crude oil production is accomplished in each of the production tubings.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Flow Control (AREA)
  • Control Of Positive-Displacement Air Blowers (AREA)
  • Feeding And Controlling Fuel (AREA)

Abstract

Système de régulation de la production d'un puits de pétrole dont le pétrole est extrait au gaz. Ce système comprend une duse (1) à commande dynamique destinée à régler le débit de pétrole brut provenant d'une colonne de production (2) du puits. La duse (1) est commandée par un module de commande (MC) comprenant un régulateur PID (PID) qui est réglé de façon à commander de manière dynamique l'ouverture de la duse (1) afin que la pression CHP (pression au niveau de la tête du tubage) du conduit d'injection de gaz d'extraction soit réduite et stabilisée. Le système est capable d'augmenter et de stabiliser la production de pétrole brut de manière précise et sans avoir recours à un équipement de fond de trou.

Claims (6)

  1. Système de régulation de l'extraction de pétrole brut par un tubage d'extraction qui s'étend dans un puits extrayant du pétrole sous l'action d'un gaz, dans lequel le gaz de relèvement est injecté en un emplacement situé en fond de puits, le système comprenant :
    un étrangleur variable pour ajuster l'écoulement de pétrole brut dans ledit tubage d'extraction; et
    un module de régulation pour réguler dynamiquement l'ouverture de l'étrangleur, lequel module de régulation utilise comme signal d'entrée la pression mesurée par un manomètre dans le conduit d'injection de gaz de relèvement;
       caractérisé en ce que le module de régulation comprend un régulateur PID qui est réglé pour réguler dynamiquement l'ouverture de l'étrangleur de telle sorte que la pression du fluide dans ledit conduit d'injection de gaz de relèvement soit minimisée et stabilisée.
  2. Système selon la revendication 1, dans lequel le module de régulation comprend en outre un régulateur maítre qui incorpore un algorithme à logique floue pour générer pour le régulateur PID un point de réglage de la pression dans le conduit d'injection de gaz de relèvement.
  3. Système selon l'une quelconque des revendications précédentes, dans lequel l'étrangleur variable et le module de régulation sont situés à la surface du sol, en un emplacement proche de la tête du puits extrayant du pétrole sous l'action d'un gaz.
  4. Système selon l'une quelconque des revendications précédentes, dans lequel le puits comprend une pluralité de tubages d'extraction de pétrole brut et dans lequel du gaz de relèvement est injecté en différents emplacements de fond de puits dans les différents tubages d'extraction par l'intermédiaire d'un conduit commun d'injection de gaz qui est formé au moins en partie par un espace annulaire situé entre les tubages d'extraction et un cuvelage de puits, chaque conduit d'extraction étant équipé d'un système de régulation de l'extraction selon l'une quelconque des revendications précédentes.
  5. Système selon l'une quelconque des revendications précédentes, dans lequel l'étrangleur variable est équipé d'un moyen d'entraínement qui utilise comme source d'énergie la pression hydraulique élevée du gaz de relèvement dans le conduit d'injection de gaz de relèvement.
  6. Système selon la revendication 5, dans lequel le moyen d'entraínement est constitué d'un moteur à déplacement positif dont une entrée est reliée au conduit d'injection de gaz de relèvement et dont une sortie est reliée au tubage d'extraction de l'un des conduits d'extraction.
EP96927604A 1995-07-24 1996-07-23 Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz Expired - Lifetime EP0840836B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP96927604A EP0840836B1 (fr) 1995-07-24 1996-07-23 Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP95202038A EP0756065A1 (fr) 1995-07-24 1995-07-24 Système de contrÔle de la production d'un puits de pétrole avec ascension au gaz
EP95202038 1995-07-24
PCT/EP1996/003285 WO1997004212A1 (fr) 1995-07-24 1996-07-23 Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz
EP96927604A EP0840836B1 (fr) 1995-07-24 1996-07-23 Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz

Publications (2)

Publication Number Publication Date
EP0840836A1 EP0840836A1 (fr) 1998-05-13
EP0840836B1 true EP0840836B1 (fr) 2000-10-11

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Family Applications (2)

Application Number Title Priority Date Filing Date
EP95202038A Withdrawn EP0756065A1 (fr) 1995-07-24 1995-07-24 Système de contrÔle de la production d'un puits de pétrole avec ascension au gaz
EP96927604A Expired - Lifetime EP0840836B1 (fr) 1995-07-24 1996-07-23 Systeme de regulation de la production d'un puits de petrole dont le petrole est extrait au gaz

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP95202038A Withdrawn EP0756065A1 (fr) 1995-07-24 1995-07-24 Système de contrÔle de la production d'un puits de pétrole avec ascension au gaz

Country Status (7)

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EP (2) EP0756065A1 (fr)
CA (1) CA2226289C (fr)
EA (1) EA000484B1 (fr)
MY (1) MY119607A (fr)
NO (1) NO311450B1 (fr)
OA (1) OA10655A (fr)
WO (1) WO1997004212A1 (fr)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO982973D0 (no) 1998-06-26 1998-06-26 Abb Research Ltd Anordning ved oljebr°nn
FR2783557B1 (fr) 1998-09-21 2000-10-20 Elf Exploration Prod Methode de conduite d'un puits de production d'hydrocarbures active par injection de gaz
FR2783559B1 (fr) 1998-09-21 2000-10-20 Elf Exploration Prod Methode de conduite d'un dispositif de transport d'hydrocarbures entre des moyens de production et une unite de traitement
US6182756B1 (en) * 1999-02-10 2001-02-06 Intevep, S.A. Method and apparatus for optimizing production from a gas lift well
NO313677B1 (no) 2000-12-06 2005-10-24 Abb Research Ltd Slug kontrollering
FR2822191B1 (fr) 2001-03-19 2003-09-19 Inst Francais Du Petrole Methode et dispositif pour neutraliser par injection controlee de gaz, la formation de bouchons de liquide au pied d'un riser se raccordant a une conduite d'acheminement de fluides polyphasiques
MY129058A (en) * 2001-10-01 2007-03-30 Shell Int Research Method and system for producing an oil and gas mixture through a well
WO2006067151A1 (fr) * 2004-12-21 2006-06-29 Shell Internationale Research Maatschappij B.V. Controle du debit d'un fluide polyphasique en provenance d'un puits
GB2429797B (en) * 2005-08-31 2010-09-08 Genesis Oil And Gas Consultant Pipeline control system
FR2942265B1 (fr) 2009-02-13 2011-04-22 Total Sa Procede de conduite d'installation de production d'hydrocarbures
US10612350B2 (en) * 2013-10-11 2020-04-07 Raise Production Inc. Crossover valve system and method for gas production
FR3011874B1 (fr) 2013-10-14 2015-11-06 Total Sa Installation de production d’hydrocarbures, procede de production et procede de mise a niveau
CA2968489C (fr) 2014-11-30 2018-11-27 Abb Schweiz Ag Procede et systeme de maximisation de la production d'un puits avec un pompage pneumatique assiste par gaz
AU2015387477A1 (en) * 2015-03-25 2017-09-07 Landmark Graphics Corporation Fuzzy logic flow regime identification and control
MX2020002900A (es) 2017-09-15 2020-09-03 Intelligas Csm Services Ltd Sistema y método para el levantamiento artificial por gas a baja presión.

Family Cites Families (4)

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Publication number Priority date Publication date Assignee Title
US2298834A (en) * 1940-05-24 1942-10-13 Standard Oil Dev Co Means for producing oil wells
US5014789A (en) * 1986-07-07 1991-05-14 Neville Clarke Method for startup of production in an oil well
US5172717A (en) * 1989-12-27 1992-12-22 Otis Engineering Corporation Well control system
FR2672936B1 (fr) * 1991-02-14 1999-02-26 Elf Aquitaine Procede de controle du debit de production d'un puits petrolier.

Also Published As

Publication number Publication date
NO311450B1 (no) 2001-11-26
EA000484B1 (ru) 1999-08-26
OA10655A (en) 2002-09-19
MY119607A (en) 2005-06-30
NO980301L (no) 1998-03-24
EP0840836A1 (fr) 1998-05-13
CA2226289A1 (fr) 1997-02-06
NO980301D0 (no) 1998-01-23
EA199800149A1 (ru) 1998-08-27
EP0756065A1 (fr) 1997-01-29
CA2226289C (fr) 2008-01-15
WO1997004212A1 (fr) 1997-02-06

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