US 12,492,761 B2
Coupled connection for tight clearance casing strings in oil and gas wells
Eugene J. Mannella, Richmond, TX (US)
Assigned to GB CONNECTIONS LLC, Houston, TX (US)
Filed by GB CONNECTIONS LLC, Houston, TX (US)
Filed on Jun. 14, 2022, as Appl. No. 17/840,018.
Prior Publication US 2023/0399898 A1, Dec. 14, 2023
Int. Cl. F16L 15/00 (2006.01); E21B 17/042 (2006.01)
CPC F16L 15/001 (2013.01) [E21B 17/042 (2013.01); F16L 15/002 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A casing assembly, comprising:
tubulars each having a pipe body and pin ends, the pipe body having a first outer diameter and having a bore with a first inner diameter, the pipe body having a first critical cross-section defined by the first outer diameter and the first inner diameter, a first strength of the pipe body being defined by the first critical cross-section, the pipe body having a pipe tension resistance and a pipe pressure resistance defined by the first strength, each of the pin ends having a turn-down recessed to a second outer diameter smaller than the first outer diameter, the turn-down having a second critical cross-section defined by the second outer diameter and the first inner diameter, a second strength of the turn-down being defined by the second critical cross-section, each of the pin ends tapering inward from the second outer diameter at the turn-down to a third outer diameter at a pin nose of the pin end, the pin end having a third critical cross-section defined by the third outer diameter and the first inner diameter, a third strength of the pin end being defined by the third critical cross-section, each of the pin ends having a pin thread formed externally on a portion thereof; and
couplings each having a cylindrical body, the cylindrical body having opposing ends and having a through-bore, the cylindrical body having a fourth outer diameter, the through-bore having a second inner diameter, the through-bore having first and second portions of box thread formed internally thereon, the second inner diameter at the first portion tapering outward from a center of the through-bore to one of the opposing ends, the second inner diameter at the second portion tapering outward from the center of the through-bore to the other of the opposing ends, the couplings each having at least one fourth critical cross-section defined by the fourth outer diameter and the second inner diameter, a fourth strength of the coupling being defined by the at least one fourth critical cross-section,
the pin threads of opposing ones of the pin ends being configured to thread respectively in a connection to a respective one of the first and second portions of the box thread of the couplings,
the pin noses of the opposing ones of the pin ends being configured to meet in the connection in the center of the couplings, the pin noses having a nose bearing area configured to engage with a torque resistance against one another,
wherein (a) at least the second critical cross-section of the turn-down is selected to increase the at least one fourth critical cross-section of the coupling relative to the first critical cross-section of the pipe body and (b) at least the third strength of the pin end defined by the third critical cross-section is iteratively selected relative to the fourth strength of the coupling defined by the at least one fourth critical cross-section of the coupling to achieve: a connection tension resistance for the connection at a first targeted level that is at least 70 percent of the pipe tension resistance of the pipe body, and a connection pressure resistance for the connection at a second targeted level that is a least 70 percent of the pipe pressure resistance of the pipe body.