Methods and systems for long-term monitoring of a well system during abandonment

Abstract

For long-term abandonment and monitoring of well systems, a series of barriers are formed within a formation and within a casing of a well to prevent materials from leaking from the well. Formation barriers are formed within the formation at the location of perforations in the casing and along the annulus. A series of casing barriers and fluid barriers are formed within the casing of the well. One or more sensors are formed within the barriers to monitor the conditions around the barriers over long periods of time. The sensors can be configured to measure the conditions around the one or more barriers during formation of the one or more barriers and over long periods of time after the one or more barriers are formed.

What is claimed is: 
     
         1 . A method for abandoning a well system, the well system including a formation, a casing providing access to the formation, and an annulus formed around the casing, the method comprising:
 forming, within the formation, a first barrier that comprises a first set of sensors located within the first barrier, wherein the first barrier is formed within the formation adjacent to perforations in the casing and the annulus; and   forming, within the casing, at least one additional barrier that comprises an additional set of sensors located within the at least one additional barrier.   
     
     
         2 . The method of  claim 1 , the method further comprising:
 forming, within the annulus, at least one annulus barrier that comprises another set of sensors located within the annulus barrier.   
     
     
         3 . The method of  claim 1 , wherein forming the first barrier comprises:
 injecting a fluid into the formation through the perforations in the casing and the annulus, wherein the fluid induces damage in the formation and prevents migration of formation fluids to form the first barrier; and   introducing the first set of sensors into the fluid during injection, wherein the first set of sensors is introduced into the fluid in a manner to cause the first set of sensors to be dispersed within the first barrier adjacent to the perforations in the casing and the annulus.   
     
     
         4 . The method of  claim 3 , wherein the fluid comprises a low-viscosity fluid that penetrates a rock matrix of the formation to damage the rock matrix and that prevents migration of formation fluids, over time, to form the first barrier. 
     
     
         5 . The method of  claim 1 , wherein forming the at least one additional barrier comprises:
 forming, within the casing, a second barrier that comprises a second set of sensors located within the second barrier.   
     
     
         6 . The method of  claim 5 , wherein forming the second barrier comprises:
 injecting cement into the casing, wherein the cement hardens to form the second barrier; and   introducing the second set of sensors into the cement during injection, wherein the second set of sensors is introduced into the cement in a manner to cause the second set of sensors to be dispersed within the second barrier.   
     
     
         7 . The method of  claim 5 , wherein the second barrier is formed within the casing adjacent to the perforations in the casing and the annulus. 
     
     
         8 . The method of  claim 5 , the method further comprising:
 forming, within the casing, a third barrier that comprises a third set of sensors located within the third barrier, wherein the third barrier is formed at a higher location in the casing relative to the second barrier.   
     
     
         9 . The method of  claim 8 , wherein forming the third barrier comprises:
 injecting cement into the casing, wherein the cement hardens to form the third barrier; and   introducing the third set of sensors into the cement during injection, wherein the third set of sensors is introduced into the cement in a manner to cause the third set of sensors to be dispersed within the third barrier.   
     
     
         10 . The method of  claim 1 , the method further comprises:
 injecting a fluid between the second barrier and the third barrier; and   introducing a fourth set of sensors into the fluid during injection, wherein the fourth set of sensors is introduced into the fluid in a manner to cause the fourth set of sensors to be dispersed within the fluid.   
     
     
         11 . The method of  claim 1 , wherein the first set of sensors comprises at least one of pressure sensor, a temperature sensor, a force sensor, a stress sensor, a corrosion sensor, an acoustic sensor, a seismic sensor, and a chemical detection sensor. 
     
     
         12 . The method of  claim 1 , wherein the additional set of sensors comprises at least one of pressure sensor, a temperature sensor, a force sensor, a stress sensor, a corrosion sensor, an acoustic sensor, a seismic sensor, and a chemical detection sensor. 
     
     
         13 . The method of  claim 1 , the method further comprising:
 testing an integrity of at least one of the first barrier and the at least one additional barrier.   
     
     
         14 . The method of  claim 13 , wherein testing the integrity, comprises:
 applying a positive pressure to at least one of the first barrier and the at least one additional barrier; and   measuring conditions around at least one of the first barrier and the at least one additional barrier using at least one of the first set of sensors and the additional set of sensors.   
     
     
         15 . The method of  claim 13 , wherein testing the integrity, comprises:
 applying a negative pressure to at least one of the first barrier and the at least one additional barrier; and   measuring conditions around at least one of the first barrier and the at least one additional barrier using at least one of the first set of sensors and the additional set of sensors.   
     
     
         16 . A method for abandoning a well system, the well system including a formation, a casing providing access to the formation, and an annulus formed around the casing, the method comprising:
 forming a set of barriers within the well system, wherein the set of barriers are formed to prevent leaking of fluid and gases from the well system; and   introducing, during formation of the set of barriers, a set of sensors to each barrier in the set of barriers, wherein the set of sensors is configured to monitor conditions around the set of barriers.   
     
     
         17 . The method of  claim 16 , wherein forming the set of barriers comprises:
 forming, within the formation, a first barrier that comprises a first set of sensors located within the first barrier, wherein the first barrier is formed within the formation adjacent to perforations in the casing and the annulus.   
     
     
         18 . The method of  claim 16 , wherein forming the set of barriers comprises:
 forming, within the casing, a second barrier that comprises a second set of sensors located within the second barrier.   
     
     
         19 . The method of  claim 18 , wherein the second barrier is formed within the casing adjacent to the perforations in the casing and the annulus. 
     
     
         20 . The method of  claim 18 , wherein forming the set of barriers comprises:
 forming, within the casing, a third barrier that comprises a third set of sensors located within the third barrier, wherein the third barrier is formed at a higher location in the casing relative to the second barrier.   
     
     
         21 . The method of  claim 20 , wherein forming the set of barrier comprises:
 injecting a fluid between the second barrier and the third barrier; and   introducing a fourth set of sensors into the fluid during injection, wherein the fourth set of sensors is introduced into the fluid in a manner to cause the fourth set of sensors to be dispersed within the fluid.   
     
     
         22 . The method of  claim 16 , the method further comprising:
 testing, during formation, an integrity of at least one of the set of barriers using the set of sensors formed within the at least one of the set of barriers under test.   
     
     
         23 . The method of  claim 16 , wherein forming the set of barriers comprises:
 forming, within the annulus, an additional barrier that comprises an additional set of sensors located within the additional barrier.   
     
     
         24 . A method for monitoring a well system, the well system including a formation, a casing providing access to the formation, and an annulus formed around the casing, the method comprising:
 forming, within the well system, a set of barriers, each barrier in the set of barriers comprising a set of sensors, wherein the set of barriers are formed to prevent leaking of fluid and gases from the well system; and   monitoring at least one of the set of sensors to identify leaking in the well system.   
     
     
         25 . The method of  claim 24 , wherein the at least one of the set of sensors is monitored during formation of the set of barriers to identify leaking in the well system. 
     
     
         26 . The method of  claim 24 , wherein the at least one of the set of sensors is monitored after formation of the set of barriers to identify leaking in the well system. 
     
     
         27 . The method of  claim 24 , wherein monitoring the at least one of the set of sensors comprises:
 communicating with the at least one of the set of sensors with a wireless signal.   
     
     
         28 . The method of  claim 27 , wherein the wireless signal is relayed to the at least one of the set of sensors by anther sensor in the set of sensors. 
     
     
         29 . The method of  claim 24 , the method further comprising:
 powering the set of sensors.   
     
     
         30 . The method of  claim 29 , wherein powering the set of sensors comprises introducing an electromagnetic signal to the set of sensors to induce power in the set of sensors. 
     
     
         31 . The method of  claim 29 , wherein powering the set of sensors comprises introducing an electrical current to the set of sensors via wire. 
     
     
         32 . A sensor for measuring condition is a well system during abandonment of the well system, comprising:
 sensing hardware for measuring at least one condition in a well;   a power supply coupled to the sensing hardware and configured to power the sensing hardware; and   communication hardware coupled to the sensing hardware and configured to communicate measurements of the at least one condition to a monitoring system.   
     
     
         33 . The sensor of  claim 32 , further comprising:
 at least one wire coupled to the monitoring system.   
     
     
         34 . The sensor of  claim 33 , wherein the at least one wire servers as a communication pathway to communicate the measurements of the at least one condition to the monitoring system. 
     
     
         35 . The sensor of  claim 33 , wherein the at least one wire is coupled to an external power supply to power the sensor. 
     
     
         36 . The sensor of  claim 33 , wherein the at least one wire is coupled to a casing in the well. 
     
     
         37 . The sensor of  claim 32 , wherein the communication hardware comprises:
 an antenna; and   a transceiver coupled to the antenna.   
     
     
         38 . The sensor of  claim 32 , wherein the communication hardware is configured to power the sensor from electromagnetic waves received by the communication hardware.