Universal cementing plug

A cementing plug for use in a cementing casing in a well, comprising:

• a body member defining a central opening therethrough and having a longitudinal axis;
• an elastomeric jacket disposed around said body member and having a wiper cup extending therefrom, said wiper cup defining a conical outer surface extending upwardly and outwardly at an acute angle with respect to said longitudinal axis, wherein said outer surface is deflected into substantially cylindrical, wiping engagement with an inner surface of a casing when the plug is disposed therein;
• an insert disposed in said central opening for at least temporary closure thereof, said insert being a selected one of a plurality of inserts;
• and
• wherein said insert is a shearable member adapted for shearing and opening said central opening when a predetermined differential pressure is applied across said shearable member or a substantially non-shearable disk adapted for substantially permanent closure of said central opening.

A cementing plug apparatus for use in cementing a length of well casing in a well, said apparatus comprising:

• a pair of substantially identical plug subassemblies, each of said plug subassemblies comprising:
• a generally cylindrical body member defining a central opening longitudinally therethrough;
• and
• an outer jacket disposed around said body member, said jacket having a resilient wiper cup extending therefrom adapted for wiping engagement with an inner surface of said length of casing;
• a shearable insert positionable in one of said body members for temporarily closing said central opening in said one body member and for rupturing and thereby opening said central opening in response to a predetermined differential pressure thereacross;
• and
• a substantially non-shearable insert positionable in the other of said body members for substantially permanently closing said central opening in the other body member.

A cementing plug apparatus for use in cementing casing in a well, said apparatus comprising:

• a first cementing plug comprising:
• a first body member defining a first central opening therethrough;
• a first jacket disposed on said first body member, said first jacket having a wiper cup extending therefrom adapted for wiping engagement with an inner surface of the casing;
• and
• a replaceable first insert disposed adjacent to said first body member for temporarily closing said first central opening and subsequently shearing when subjected to a predetermined pressure, thereby opening said first central opening;
• and
• a second cementing plug comprising:
• a second body member defining a second central opening therethrough;
• a second jacket disposed on said second body member, said second jacket having a wiper cup extending therefrom adapted for wiping engagement with an inner surface of the casing;
• and
• a replaceable second insert disposed adjacent to said second body member for substantially permanently closing said second central opening.

A plug for use in a well casing, comprising:

• a body member defining a central opening therethrough;
• a jacket disposed around said body member and having a wiper cup extending therefrom for engaging an inner surface of the casing;
• and
• an insert disposed in said central opening for at least temporary closure thereof, wherein said insert is a shearable member or a substantially non-shearable disk.

A plug for use in a well casing, comprising:

• a body member defining a central opening therethrough;
• and
• an insert positioned for at least temporary closure of said central opening, wherein said insert comprises:
• an outer ring portion, and
• an inner portion extending from said outer ring portion, wherein said inner portion is thinner than said outer ring portion and has a variable thickness.

A method for wiping an inner surface of a tubular member comprising:

• providing in the tubular member a plug having two conical wipers one of which overlaps the other in an axial direction, the wipers engaging the inner surface in a manner so that each wiper is deflected into a substantially cylindrical shape in engagement with the inner surface;
• and applying pressure from one end of the tubular member to move the plug within the tubular member;
• and
• providing an insert across a central opening in the plug for closure thereof, wherein the insert is a shearable member adapted for shearing and opening the central opening when a predetermined pressure is applied across the shearable member or a substantially non-shearable member adapted for substantially permanent closure of the central opening.

A method for wiping an inner surface of a tubular member comprising:

• introducing a first plug into one end of the tubular member;
• introducing a fluid into the one end of the tubular member to force the first plug downwardly in the tubular member to displace any fluid from the tubular member below the first plug;
• providing at least two wipers on the first plug, one of the wipers overlapping the other wiper in an axial direction so that, as the plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein each wiper of the first plug is sized to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface;
• terminating the step of introducing the fluid into the tubular member;
• introducing a second plug into the tubular member end;
• forcing the second plug downwardly through the tubular member so that it forces the fluid and the first plug downwardly in the tubular member;
• establishing a differential pressure across the first plug to open the first plug and allow the fluid to pass through the first plug and exit the other end of the tubular member;
• and
• providing at least two wipers on the second plug one of which overlaps the other in an axial direction, so that as the second plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein each wiper of the second plug is sized to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface.

A method for wiping an inner surface of a tubular member comprising:

• introducing a first plug into one end of the tubular member;
• introducing a fluid into the one end of the tubular member to apply pressure to the first plug to force it downwardly in the tubular member to displace any fluid in the tubular member below the first plug;
• providing at least two wipers on the first plug, one of the wipers overlapping the other in an axial direction so that, as the first plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, and so that, as a wiper on the first plug closest to the one end of the tubular member wears, the pressure will be applied to the other wiper of the same plug;
• terminating the step of introducing the fluid into the tubular member;
• introducing a second plug into the tubular member end;
• applying pressure to the second plug to force it downwardly through the tubular member so that it forces the fluid and the first plug downwardly in the tubular member;
• establishing a differential pressure across the first plug to open the first plug and allow the fluid to pass through the first plug and exit the other end of the tubular member;
• and
• providing at least two wipers on the second plug, one the wipers overlapping the other in an axial direction so that, as the second plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein as a wiper on the second plug closest to the one end of the tubular member wears, the pressure will be applied to the other wiper of the same plug.

A method for wiping an inner surface of a tubular member comprising:

• providing in the tubular member a plug having two axially-spaced, conical wipers that engage the inner surface in a manner so that each wiper is deflected into a substantially cylindrical shape in engagement with the inner surface;
• applying pressure from one end of the tubular member to move the plug within the tubular member;
• providing an additional plug in the tubular member having two axially-spaced, conical wipers that engage the inner surface in a manner so that the wiper is deflected into a substantially cylindrical shape in engagement with the inner surface;
• applying pressure from one end of the tubular member to move the additional plug within the tubular member;
• and
• providing a shearable insert across a central opening in the plug closest to the end of the tubular member for closure thereof, the insert being adapted for shearing and opening the central opening in the latter plug when a predetermined pressure is applied across the shearable insert, and further comprising providing a substantially non-shearable insert across a central opening in the other plug for substantially permanent closure of the opening in the second plug.

A method for wiping a tubular member containing fluid comprising:

• introducing a first plug into one end of the tubular member;
• introducing fluid into the one end of the tubular member to force the first plug downwardly in the tubular member to displace the fluid from the tubular member;
• providing at least two axially spaced wipers on the first plug so that, as the plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein each wiper of the first plug is sized to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface;
• terminating the step of introducing the fluid into the tubular member;
• introducing a second plug into the tubular member end which is identical to the first plug;
• forcing the second plug downwardly through the tubular member so that it forces the fluid and the first plug downwardly in the tubular member;
• establishing a differential pressure across the first plug to open the first plug and allow the fluid to pass through the first plug and exit the other end of the tubular member;
• and
• providing at least two axially spaced wipers on the second plug so that as the second plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein each wiper of the second plug is sized to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface.

A method for wiping a tubular member containing fluid in a well comprising:

• introducing a first plug into one end of the tubular member;
• introducing fluid into the one end of the tubular member to force the first plug downwardly in the tubular member to displace the fluid from the tubular member;
• providing at least two axially spaced wipers on the first plug so that, as the plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein each wiper of the first plug is sized to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface;
• terminating the step of introducing the fluid into the tubular member;
• introducing a second plug into the tubular member end;
• forcing the second plug downwardly through the tubular member so that it forces the fluid and the first plug downwardly in the tubular member;
• establishing a differential pressure across the first plug to open the first plug and allow the fluid to pass through the first plug and exit the other end of the tubular member;
• providing at least two axially spaced wipers on the second plug so that as the second plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein each wiper of the second plug is sized to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface;
• and
• providing a shearable insert across a central opening in the first plug for closure thereof and adapted for shearing and opening the central opening in the first plug when a predetermined pressure is applied across the shearable insert, and further comprising providing a substantially non-shearable insert across a central opening in the second plug for substantially permanent closure of the opening in the second plug.

A method for wiping a tubular member containing fluid comprising:

• introducing a first plug into one end of the tubular member;
• introducing fluid into the one end of the tubular member to apply pressure to the first plug to force it downwardly in the tubular member to displace the fluid from the tubular member;
• providing at least two axially spaced wipers on the first plug so that, as the first plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein as a wiper on the first plug closest to the one end of the tubular member wears, the pressure will be applied to the other wiper of the first plug;
• terminating the step of introducing the fluid into the tubular member;
• introducing a second plug into the tubular member end;
• applying pressure to the second plug to force it downwardly through the tubular member so that it forces the fluid and the first plug downwardly in the tubular member;
• establishing a differential pressure across the first plug to open the first plug and allow the fluid to pass through the first plug and exit the other end of the tubular member;
• providing at least two axially spaced wipers on the second plug so that, as the second plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein as a wiper on the second plug closest to the one end of the tubular member wears, the pressure will be applied to the other wiper of the second plug;
• and
• sizing each wiper to engage the inner surface in a manner so that it is deflected into a substantially cylindrical wiping engagement with the inner surface.

A method for wiping a tubular member containing fluid in a well comprising:

• introducing a first plug into one end of the tubular member;
• introducing fluid into the one end of the tubular member to apply pressure to the first plug to force it downwardly in the tubular member to displace the fluid from the tubular member;
• providing at least two axially spaced wipers on the first plug so that, as the first plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein as a wiper on the first plug closest to the one end of the tubular member wears, the pressure will be applied to the other wiper of the first plug;
• terminating the step of introducing the fluid into the tubular member;
• introducing a second plug into the tubular member end;
• applying pressure to the second plug to force it downwardly through the tubular member so that it forces the fluid and the first plug downwardly in the tubular member;
• establishing a differential pressure across the first plug to open the first plug and allow the fluid to pass through the first plug and exit the other end of the tubular member;
• providing at least two axially spaced wipers on the second plug so that, as the second plug passes downwardly in the tubular member, it wipes the inner surface of the tubular member of any accumulated fluid, wherein as a wiper on the second plug closest to the one end of the tubular member wears, the pressure will be applied to the other wiper of the second plug;
• and
• providing a shearable insert across a central opening in the first plug for closure thereof and adapted for shearing and opening the central opening in the first plug when a predetermined pressure is applied across the shearable insert, and further comprising
• providing a substantially non-shearable insert across a central opening in the second plug for substantially permanent closure of the opening in the second plug.

A plug for wiping an inner surface of a tubular member, the plug comprising:

• a body member;
• a lip extending outwardly from the body member and defining a wiping surface for wiping the inner surface of the tubular member;
• and
• at least two axially spaced wiper cups having a conical outer surface extending outwardly around the body member and defining a wiping surface for wiping the inner surface of the tubular member, wherein the length of the wiping surface of each of the wiper cups is greater than the length of the wiping surface of the lip.

A plug for wiping an inner surface of a tubular member, the plug comprising:

• a body member;
• a lip extending outwardly from the body member and defining a wiping surface for wiping the inner surface of the tubular member;
• and
• at least two axially spaced wiper cups extending outwardly from the body member and defining a wiping surface for wiping the inner surface of the tubular member;
• wherein the axial length of the wiping surface of each of the wiper cups is greater than the maximum radial width of the lip;
• and
• wherein each of the wiper cups is deflected into a substantially cylindrical shape in engagement with the inner surface.

A method of wiping fluid from a tubular member:

• introducing fluid into a tubular member;
• providing a plug having a body member, a lip and at least two axially spaced wiper cups having a conical outer surface, wherein each wiper cup defines a wiping surface for wiping an inner surface of the tubular member, wherein:
• (a) the length of the wiping surface of each of the wiper cups is greater than the length of the wiping surface of the lip, or
• (b) the axial length of the wiping surface of each of the wiper cups is greater than the maximum radial width of the lip;
• and
• moving the plug in the tubular member to wipe the fluid.