Methods for Introducing Pulsing to Cementing Operations

Abstract

A method for bonding a well bore to a casing may include several steps. Casing may be introduced into the well bore and pulses of fluid may be directed from within the casing into the well bore. An annulus between an inner surface of the well bore and an outer surface of the casing may be filled with fluid. A method for reducing fluid or gas migration into a fluid in the annulus may include inducing pressure pulses in the fluid before the fluid has cured.

1 . A method for bonding a well bore to a casing therein, comprising the steps of:
 introducing the casing into the well bore;   directing pulses of fluid from within the casing into the well bore; and   filling an annulus between an inner surface of the well bore and an outer surface of the casing with the fluid.   
   
   
       2 . The method of  claim 1 , wherein the fluid is a cement. 
   
   
       3 . The method of  claim 1 , wherein the step of directing pulses of fluid is performed while moving the casing further into the well bore. 
   
   
       4 . The method of  claim 1 , further comprising the step of selecting a frequency and pressure level for the pulses of fluid so as to reduce filter cake formed on the inner surface of the well bore. 
   
   
       5 . The method of  claim 2 , further comprising the step of selecting a frequency and pressure level for the pulses of fluid so as to reduce the amount non-cement material on the casing. 
   
   
       6 . The method of  claim 5 , further comprising the step of selecting a frequency and pressure level for the pulses of fluid so as to reduce filter cake formed on the inner surface of the well bore, such that the pulses have a dual-step profile. 
   
   
       7 . The method of  claim 1 , further comprising the step of vibrating the casing at a resonance frequency for the casing. 
   
   
       8 . The method of  claim 7 , wherein the step of vibrating the casing at a resonance frequency comprises the step of directing pulses of fluid into the well bore at a frequency and pressure selected to induce resonance vibrations in the casing. 
   
   
       9 . The method of  claim 1 , further comprising the step of vibrating well fluid at a resonance frequency for the well fluid. 
   
   
       10 . (canceled) 
   
   
       11 . (canceled) 
   
   
       12 . A method for reducing fluid or gas migration into a fluid in an annulus formed between a surface of a well bore in a formation and a casing, comprising the step of inducing pressure pulses in the fluid before the fluid has cured, further comprising the step of selecting a frequency and amplitude for the pressure pulses such that the pressure pulses prevent shear damage of the fluid during curing. 
   
   
       13 . The method of  claim 12 , wherein the step of inducing pressure pulses in fluid before the fluid has cured comprises the step of inducing a low-amplitude pressure pulse. 
   
   
       14 . The method of  claim 12 , wherein the step of inducing pressure pulses in fluid before the fluid has cured comprises the step of inducing a low-frequency pressure pulse. 
   
   
       15 . A method for reducing fluid or gas migration into a fluid in an annulus formed between a surface of a well bore in a formation and a casing, comprising the step of inducing pressure pulses in the fluid before the fluid has cured, wherein the step of inducing pressure pulses in fluid before the cement has cured comprises the step of inducing a pressure pulse having a dual-step profile.