Classifications

• • 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
  • E21B43/02—Subsoil filtering
  • E21B43/10—Setting of casings, screens, liners or the like in wells
  • E21B43/103—Setting of casings, screens, liners or the like in wells of expandable casings, screens, liners, or the like
  • E21B43/108—Expandable screens or perforated liners
• • 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
  • E21B43/02—Subsoil filtering
  • E21B43/08—Screens or liners
  • E21B43/086—Screens with preformed openings, e.g. slotted liners
• • 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
  • E21B43/02—Subsoil filtering
  • E21B43/10—Setting of casings, screens, liners or the like in wells
  • E21B43/103—Setting of casings, screens, liners or the like in wells of expandable casings, screens, liners, or the like

Definitions

• the invention relates to an expandable well screen for preventing migration of solid particles into a hydrocarbon fluid production well.
• the invention relates to an expandable well screen which comprises a number of filter sheets which are secured in an iris-shaped configuration and co-axial to an expandable slotted carrier tube such that as a result of expansion of the tube the amount of overlap between adjacent filter sheets is reduced.
• an expandable well screen is disclosed in applicant's co-pending international patent application PCT/EP96/04887.
• Figure 3 of this prior art reference discloses that the filter sheets consist of plates in which a series of circular perforations are present. The size of these perforations is chosen such that solid particles larger than the size of the hole are prevented from flowing into the well.
• a suitable expandable slotted carrier tube for use with the screen is disclosed in international patent application PCT/EP93/01460.
• An object of the present invention is to provide a well screen comprising an iris-shaped configuration of filter sheets which do not buckle and which slide easily relative to each other and relative to the carrier tube during the process of expanding the carrier tube.
• the well screen according to the invention thereto comprises filter sheets having slots which are oriented in a substantially circumferential orientation with respect to the carrier tube.
• the reference to a circumferential arrangement of slots means that the slots each are directed in a substantially tangential orientation with respect to the carrier tube and such the slots are oriented substantially transversal to the central axis and any axial slots of the carrier tube.
• the filter sheets consist of elongate strips with staggered rows of slots in a transversal direction with respect to a longitudinal axis of each strip .
• the pattern of slots is preferably such that alternate rows are displaced up to half a slot pitch in the transverse direction, the length of the slots is greater than half the transverse slot pitch, and the pattern of slots is continued through the longitudinal edges of the strips.
• each strip is secured at regularly spaced points along its length to the expandable slotted carrier tube and that each strip is secured to the expandable slotted carrier tube at said points by either spot welding, brazing, soldering, gluing, riveting or screwing the strip to the tube at each of said points .
• Fig. 1 is a cross-sectional view of a well-screen comprising an iris-shaped configuration of filter sheets according to the invention
• Fig. 2 is a longitudinal sectional view of the well screen of Fig. 1;
• Fig. 3 is a side view of the well screen of Fig. 1 and 2 in which the protective surrounding tube has been omitted; and Fig. 4 and Fig. 4A, B, C and D show the original shape and deformation of the circumferential slots near a longitudinal edge of the filter sheets before, during and after the expansion process.
• Fig. 1 there is shown an expandable slotted carrier tube 1 which is surrounded by a well screen 2 which comprises a series of filter sheets 3 which are arranged in an iris-shaped configuration around the carrier tube 1.
• the filter sheets 3 consist of elongate rectangular strips which are each, as shown in Fig. 1 secured to the carrier tube 1 at attachment points 4 located on or close to the longitudinal centreline of the filter sheet 3 by for example spot welding, brazing, soldering, gluing, riveting or screwing at regularly spaced points along the length of the carrier tube 1.
• the attachment points are located on the nodes between the ends of the slots of the carrier tube 1.
• the filter sheets 3 overlap each other in both axial and circumferential direction such that during and after the expansion process which is illustrated in Fig. 4 at least some overlap remains between adjacent filter sheets 3.
• the protective surrounding tube 5 which is shown in Figs . 1 and 2 has been omitted to show that the filter sheets 3 each comprise a series of staggered rows of circumferential slots 6 which are oriented in a substantially tangential direction with respect to the carrier tube 1 and substantially transversal to the axial slots 7 of the carrier tube 1 and to the central axis 8 of the carrier tube 1.
• the carrier tube 1 is expanded by an expansion cone 9 during the expansion process such that the axial slots 7 deform into a diamond shape.
• the illustrated sequential opening and closing of the circumferential slots 6 provides axial flexibility to the filter sheets 3 which prevents buckling or tearing of the fragile sheets 3 during expansion of the carrier tube 1.
• the circumferential slots 6 also allow the overlapping sheets 3 to slide easily relative to each other during the expansion process.
• the filter sheets 3 may also be arranged in a shallow helix around the carrier tube 1.
• the helix angle should be selected small enough so that the deviation of the slots 6 from the tangential direction of the carrier tube 1 is less than 20 degrees.

Landscapes

• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Filtering Materials (AREA)
• Separation Of Particles Using Liquids (AREA)
• Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)
• Prostheses (AREA)

Priority Applications (9)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8228269

Family Applications (1)

Country Status (14)

Cited By (27)

Families Citing this family (2)

Citations (3)

• 1998
  • 1998-04-24 MY MYPI9801852 patent/MY119637A/en unknown
  • 1998-04-27 WO PCT/EP1998/002577 patent/WO1998049423A1/en active IP Right Grant
  • 1998-04-27 EP EP98924261A patent/EP0980462B1/de not_active Expired - Lifetime
  • 1998-04-27 ID IDW991281A patent/ID22839A/id unknown
  • 1998-04-27 DK DK98924261T patent/DK0980462T3/da active
  • 1998-04-27 AU AU76517/98A patent/AU717503B2/en not_active Expired
  • 1998-04-27 NZ NZ337859A patent/NZ337859A/xx not_active IP Right Cessation
  • 1998-04-27 DE DE69810610T patent/DE69810610T2/de not_active Expired - Lifetime
  • 1998-04-27 BR BR9809005-4A patent/BR9809005A/pt not_active IP Right Cessation
  • 1998-04-27 UA UA99116448A patent/UA57785C2/uk unknown
  • 1998-04-27 CA CA002284865A patent/CA2284865C/en not_active Expired - Lifetime
  • 1998-04-27 RU RU99125079A patent/RU2197600C2/ru active
• 1999
  • 1999-10-27 NO NO19995248A patent/NO317766B1/no not_active IP Right Cessation
  • 1999-10-28 OA OA9900238A patent/OA11211A/en unknown

Patent Citations (3)

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