Cryogenic drilling method

Abstract

A method of drilling a wellbore using a cryogenic fluid to prevent sloughing of the wellbore during drilling operations is provided. The method includes providing non-rotatable tubing constructed of a material capable of withstanding temperatures of at least about −320° F. and back pressure exerted on the tubing during the drilling operations, the tubing having an internally disposed electric power cable extending the length thereof. A drill bit constructed of materials capable of withstanding cryogenic temperatures of at least about −320° F., is operably connected to a distal end potion of the tubing. A power source capable of rotating the drill bit, the power source operable connected to the drill bit via the electric power cable such that upon activation of the power source the bit is caused to rotate. A liquid cryogenic material is injected into the tubing for cooling the drill bit of about −320° F. during drilling operations and to freezing the formation and thereby preventing sloughing of shale and infiltration of water into the wellbore.

1 . A method of drilling a wellbore without use of drilling muds to lift chips out of the wellbore and preventing sloughing of a formation into an annulus of the wellbore, the method comprising:
 providing a coil of tubing wherein the tubing is constructed of a material capable of withstanding cryogenic temperatures and a back pressure exerted on the tubing during drilling operations, the tubing having an internally disposed electric power cable extending the length thereof, the electric power cable being at approximately 75% super-compressibility because of the cryogenic temperatures inside the tubing;   a drill bit constructed of materials capable of withstanding cryogenic temperatures, the drill bit operably connected to a distal end potion of the tubing;   a power source capable of rotating the drill bit, the power source operable connected to the drill bit via the electric power cable such that upon activation of the power source the bit is caused to rotate; and   injecting a cryogenic fluid via the tubing to cool the drill bit and the formation thereby and freeze the formation and prevent sloughing of shale and infiltration of water into the wellbore.   
   
   
       2 . The method of  claim 1  wherein the tubing further comprises at least one electrically operated orifice mandrel for permitting controlled amounts of the cryogenic fluid to be injected into the annulus of the wellbore to maintain the annulus of the wellbore and the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       3 . The method of  claim 1  wherein the tubing further comprises a plurality of spatially disposed electronically operated orifice mandrels for permitting controlled amounts of cryogenic fluid to be injected into the annulus of the wellbore to maintain the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       4 . The method of  claim 3  wherein the electronically operated orifice mandrels are position at approximately every 1000 feet of the tubing. 
   
   
       5 . The method of  claim 3  wherein the cryogenic fluid is liquid nitrogen and wherein an effective amount of liquid nitrogen is used to maintain the temperature of the drill bit at approximately −320° F. and the temperature in the annulus of the wellbore and the portion of the formation surrounding the wellbore at a temperature of at least −50° F. 
   
   
       6 . The method of  claim 1  the cryogenic fluid is liquid nitrogen and wherein an effective amount of liquid nitrogen is used to maintain the temperature of the drill bit at approximately −320° F. and the temperature in the annulus of the wellbore and the portion of the formation surrounding the wellbore at a temperature of at least −50° F. 
   
   
       7 . The method of  claim 6  wherein the tubing further comprises at least one electrically operated orifice mandrel in fluid communication with the cryogenic fluid in the tubing for permitting controlled amounts of the cryogenic fluid to be injected into the annulus of the wellbore at predetermined locations to maintain the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       8 . The method of  claim 6  wherein the tubing further comprises a plurality of spatially disposed electronically operated orifice mandrels in fluid communication with the cryogenic fluid in the tubing for permitting controlled amounts of cryogenic fluid to be injected into the annulus of the wellbore at predetermined locations to maintain the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       9 . The method of  claim 9  wherein the cryogenic fluid is liquid nitrogen. 
   
   
       10 . The method of  claim 1  wherein the cryogenic fluid is liquid nitrogen. 
   
   
       11 . The method of  claim 1  further comprising providing at least one turbo expander operably connected to and in fluid communication with the annulus of the wellbore for compressing and cooling the cryogenic fluid recovered from the annulus to a temperature substantially corresponding to a temperature of the cryogenic fluid initially injected into the tubing. 
   
   
       12 . A method of drilling a wellbore using a cryogenic fluid to prevent sloughing of the wellbore during drilling operations, the method comprising:
 providing non-rotatable tubing constructed of a material capable of withstanding temperatures of at least about −320° F. and a back pressure exerted on the tubing during the drilling operations, the tubing having an internally disposed electric power cable extending the length thereof, the electric power cable being at approximately 75% super-compressibility because of the cryogenic temperatures inside the tubing;   a drill bit constructed of materials capable of withstanding cryogenic temperatures of at least about −320° F., the drill bit operably connected to a distal end potion of the tubing;   a power source capable of rotating the drill bit, the power source operable connected to the drill bit via the electric power cable such that upon activation of the power source the bit is caused to rotate; and   injecting a liquid cryogenic material into the tubing for cooling the drill bit of about −320° F. during drilling operations, the liquid cryogenic material freezing the formation and preventing sloughing of shale and infiltration of water into the wellbore.   
   
   
       13 . The method of  claim 12  wherein the liquid cryogenic material is liquid nitrogen, the liquid nitrogen is injected into the tubing at a temperature at about −320° F. and wherein the method further comprises providing at least one turbo-expander operably connected to and in fluid communication with an annulus of the wellbore for compressing and cooling liquid nitrogen and nitrogen vapor recovered from the annulus of the wellbore to a temperature of about −320° F. prior to recirculating the liquid nitrogen to the drill bit via the tubing. 
   
   
       14 . The method of  claim 13  wherein the tubing further comprises at least one electrically operated orifice mandrel for permitting controlled amounts of the cryogenic fluid to be injected into the annulus of the wellbore to maintain the annulus of the wellbore and the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       15 . The method of  claim 13  wherein the tubing further comprises a plurality of spatially disposed electronically operated orifice mandrels for permitting controlled amounts of cryogenic fluid to be injected into the annulus of the wellbore to maintain the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       16 . The method of  claim 15  wherein the electronically operated orifice mandrels are position at approximately every 1000 feet of the tubing. 
   
   
       17 . The method of  claim 15  wherein an effective amount of liquid nitrogen is injected into the wellbore to maintain the temperature of the drill bit of approximately −320° F. and the portion of the formation surrounding the wellbore of at least −50° F. 
   
   
       18 . The method of  claim 17  wherein the tubing further comprises at least one electrically operated orifice mandrel in fluid communication with the cryogenic fluid in the tubing for permitting controlled amounts of the cryogenic fluid to be injected into the annulus of the wellbore at predetermined locations to maintain the portion of the formation adjacent the wellbore at a desired cryogenic temperature. 
   
   
       19 . The method of  claim 18  wherein the tubing further comprises a plurality of spatially disposed electronically operated orifice mandrels in fluid communication with the cryogenic fluid in the tubing for permitting controlled amounts of cryogenic fluid to be injected into the annulus of the wellbore at predetermined locations to maintain the portion of the formation adjacent the wellbore at a desired cryogenic temperature.