Please download the dossier by clicking on the dossier button x
×

SYSTEM AND METHOD FOR SAFE WELL CONTROL OPERATIONS

  • US 20110214882A1
  • Filed: 03/04/2011
  • Published: 09/08/2011
  • Est. Priority Date: 03/05/2010
  • Status: Active Grant
First Claim
Patent Images

1. A system (10) for controlling a well being drilled into a subterranean formation (14), said system comprising,a tubular drill string (20) having a lower end (22) extending into a borehole 2 and an upper end (24), said tubular drill string having a drill bit (26) at its lower end,a drill string turning device (38) arranged and designed to turn said drill bit in said borehole in which a borehole annulus (18) is defined between an outer diameter of said tubular drill string and an inner diameter of said borehole,a blow-out preventer (32) arranged and designed to close said borehole from atmosphere only at a time when said drill bit is stationary,a fluid pump (40) in fluid communication with a surface fluid reservoir (42),a choke line (56) coupled between said borehole annulus and said surface fluid reservoir and arranged and designed to permit fluid communication therebetween when said blow-out preventer closes said borehole from atmosphere,a fluid injection line (48) extending between said fluid pump and said upper end of said drill string, said fluid injection line capable of providing fluid communication therebetween,said fluid injection line, said drill string, said borehole annulus and said choke line defining a fluid pathway when said blow-out preventer closes said borehole from atmosphere,an outlet flow rate measurement device (50) disposed in said choke line, said outlet flow rate measurement device arranged and designed to measure flow rate through said choke line and to generate a signal Fout(t) representative of actual choke line flow rate as a function of time (t),an outlet pressure measurement device (64) disposed in said choke line, said outlet pressure measurement device arranged and designed to measure choke line pressure and to generate a signal Pout(t) representative of actual choke line pressure as a function of time (t),a central control unit (80) arranged and designed, while said borehole is closed from atmosphere by said blow-out preventer,to receive said signals Fout(t) and Pout(t),to determine a formation fracture pressure as a function of said signals Fout(t) and Pout(t),to determine a formation pore pressure as a function of said signals Fout(t) and Pout(t),to generate a signal Pann(t) representative of pressure at a desired well bore depth as a function of time (t),to generate a signal FC(t) representative of choke line flow rate required as a function of time (t) to maintain said signal Pann(t) below said formation fracture pressure and above said formation pore pressure, andto transmit said signal FC(t), anda flow control device (70) disposed in said choke line, said flow control device arranged and designed to control fluid flow therethrough in response to said signal FC(t) transmitted and received from said central control unit, thereby controlling choke line flow ate to maintain said signal Pann(t) below said formation fracture pressure and above said formation pore pressure.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×