Downhole Tools

A downhole centralizer as claimed in claim 1, wherein the first material is selected from the group consisting of a polyphthalamide (PPA) optionally having glass reinforcement;

• a polymer of carbon monoxide and alpha-olefins;
• an aliphatic polyketone made from co-polymerization of ethylene and carbon monoxide, optionally with propylene;
• a semi-crystalline thermoplastic material with an alternating olefin-carbon monoxide structure;
• a nylon material;
• a polyamide (PA);
• polyethertherketone;
• and polytetrafluoroethylene (PTFE).

A centralizing apparatus for use in a well-bore, comprising:

• a tubular section comprising one of a well-bore casing, a liner, a screen, and a length of production tubing;
• and
• at least one downhole centralizer forming one of a well-bore casing centralizer, a liner centralizer, a screen centralizer, and a production tubing centralizer, the at least one downhole centralizer comprising a rigid tubular body configured to be received on the tubular section, in a clearance fit around the tubular section,
• the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a ring member disposed about one of the ends of the tubular member, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, the first material substantially comprising a thermoplastic polymer and a second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the tubular section such that the entire downhole centralizer is rotationally and longitudinally movable relative to the tubular section, and whereby the at least one metallic second portion is configured to radially reinforce the one of the ends of the tubular member.

A method of fixing at least one of a casing and a liner into a well-bore, the method comprising:

• locating at least one downhole centralizer on the at least one of the casing and the liner at a desired position with respect thereto, so as to provide a centralizing apparatus, the at least one downhole centralizer comprising a rigid tubular body adapted to be received on the at least one of the casing and the liner, in a clearance fit around the at least one of the casing and the liner,
• the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a ring member disposed about one of the ends of the tubular member, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, the first material substantially comprising a thermoplastic polymer, and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the at least one of the casing and the liner such that the entire downhole centralizer is rotationally and longitudinally movable relative to the at least one of the casing and the liner, and whereby the at least one metallic second portion is configured to radially reinforce the one of the ends of the tubular member;
• placing the centralizing apparatus within the well-bore;
• and
• pumping a cement slurry into an annular space between an exterior of the at least one of the casing and the liner, and the well-bore.

A method of gravel packing a well, the method comprising:

• locating at least one downhole centralizer on a screen so as to provide a centralizing apparatus, the at least one downhole centralizer comprising a rigid tubular body adapted to be received on the screen, in a clearance fit around the screen, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a ring member disposed about one of the ends of the tubular member, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, the first material substantially comprising a thermoplastic polymer, and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the screen such that the entire downhole centralizer is rotationally and longitudinally movable relative to the screen, and whereby the at least one metallic second portion is configured to radially reinforce the one of the ends of the tubular member;
• placing the centralizing apparatus within at least one of a well-bore and a perforated casing;
• and
• placing at least one of gravel and sand into an annular space between an exterior of the screen and the at least one of the well-bore and the perforated casing.

A method of completing a well, the method comprising:

• locating at least one downhole centralizer on a length of production tubing, at a desired position with respect thereto, so as to provide a centralizing apparatus, the at least one downhole centralizer comprising a rigid tubular body adapted to be received on the tubing, in a clearance fit around the tubing, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a ring member disposed about one of the ends of the tubular member, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, the first material substantially comprising a thermoplastic polymer, and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the tubing such that the entire downhole centralizer is rotationally and longitudinally movable relative to the tubing, and whereby the at least one metallic second portion is configured to radially reinforce the one of the ends of the tubular member;
• and
• placing the centralizing apparatus within at least one of a cased well-bore and a lined well-bore.

A downhole centralizer forming one of a casing centralizer, a liner, a screen centralizer, and a production tubing centralizer, the downhole centralizer comprising:

• a rigid tubular body adapted to be received on a downhole tubular element, in a clearance fit around the downhole tubular element, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a discrete additional tubular member providing at least a portion of an innermost surface of the tubular body, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, wherein at least a portion of the tubular member is radially thicker than the discrete additional tubular member, the first material substantially comprising a thermoplastic polymer and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the downhole tubular element such that the entire downhole centralizer is rotationally and longitudinally movable relative to the downhole tubular element, and whereby the at least one metallic second portion is configured to radially reinforce the tubular body.

A centralizing apparatus for use in a well-bore, comprising:

• a tubular section comprising one of a well-bore casing, a liner centralizer, a screen, and a length of production tubing;
• and
• at least one downhole centralizer forming one of a well-bore casing centralizer, a liner centralizer, a screen centralizer, and a production tubing centralizer, the at least one downhole centralizer comprising a rigid tubular body configured to be received on the tubular section, in a clearance fit around the tubular section, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a discrete additional tubular member providing at least a portion of an innermost surface of the tubular body, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, wherein at least a portion of the tubular member is radially thicker than the discrete additional tubular member, the first material substantially comprising a thermoplastic polymer, and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the tubular section such that the entire downhole centraliser is rotationally and longitudinally movable relative to the tubular section, and whereby the at least one metallic second portion is configured to radially reinforce the tubular body.

A method of fixing at least one of a casing and a liner into a well-bore, the method comprising:

• locating at least one downhole centralizer on the at least one of the casing and the liner, at a desired position with respect thereto, so as to provide a centralizing apparatus, the at least one downhole centralizer comprising a rigid tubular body adapted to be received on the at least one of the casing and the liner, in a clearance fit around the at least one of the casing and the liner, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a discrete additional tubular member providing at least a portion of an innermost surface of the tubular body, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, wherein at least a portion of the tubular member is radially thicker than the discrete additional tubular member, the first material substantially comprising a thermoplastic polymer, and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the at least one of the casing and the liner such that the entire downhole centralizer is rotationally and longitudinally movable relative to the at least one of the casing and the liner, and whereby the at least one metallic second portion is configured to radially reinforce the tubular body;
• placing the centralizing apparatus within the well-bore;
• and
• pumping a cement slurry into an annular space between an exterior of the at least one of the casing and the liner, and the well-bore.

A method of gravel packing a well, the method comprising:

• locating at least one downhole centralizer on a screen so as to provide a centralizing apparatus, the at least one downhole centralizer comprising a rigid tubular body adapted to be received on the screen, in a clearance fit around the screen, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a discrete additional tubular member providing at least a portion of an innermost surface of the tubular body, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, wherein at least a portion of the tubular member is radially thicker than the discrete additional tubular member, the first material substantially comprising a thermoplastic polymer;
• and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the screen such that the entire downhole centralizer is rotationally and longitudinally movable relative to the screen, and whereby the at least one metallic second portion is configured to radially reinforce the tubular body;
• placing the centralizing apparatus within at least one of a well-bore and a perforated casing;
• and
• placing at least one of gravel and sand into an annular space between an exterior of the screen and the at least one of the well-bore and the perforated casing.

A method of completing a well, the method comprising:

• locating at least one downhole centralizer on a length of production tubing, at a desired position with respect thereto, so as to provide a centralizing apparatus, the at least one downhole centralizer comprising a rigid tubular body adapted to be received on the tubing, in a clearance fit around the tubing, the tubular body including at least one first portion and at least one second portion, the at least one first portion and the at least one second portion being statically retained relative to one another, the at least one first portion comprising a tubular member having opposed ends and providing at least a portion of an outermost surface of the tubular body, the at least one first portion being substantially formed from a first material, and the at least one second portion comprising a discrete additional tubular member providing at least a portion of an innermost surface of the tubular body, the at least one second portion being substantially formed from a second material, the first material having a lower Young's modulus than the second material, wherein at least a portion of the tubular member is radially thicker than the discrete additional tubular member, the first material substantially comprising a thermoplastic polymer, and the second material comprising a metallic material, whereby the at least one metallic second portion is configured to cooperate with the tubing such that the entire downhole centralizer is rotationally and longitudinally movable relative to the tubing, and whereby the at least one metallic second portion is configured to radially reinforce the tubular body;
• and
• placing the centralizing apparatus within at least one of a cased well-bore and a lined well-bore.