Method for downhole leak detection

Patent metadata

Field	Value
Publication number	US-2017275987-A1
Application number	US-201615079157-A
Country	US
Kind code	A1
Filing date	Mar 24, 2016
Priority date	Mar 24, 2016
Publication date	Sep 28, 2017
Grant date	—

Abstract

An integrated and rigless method of determining the location and the type of damage in casing or tubing of a wellbore that involves recording a thickness profile of the casing or tubing, a temperature log, and a noise log along the depth of the wellbore, followed by locating the damage from the thickness profile, and determining the type of damage from the temperature log and the noise log.

First claim

1 : An integrated method of determining location and type of a damage in a casing of a well, comprising:
logging thickness of the casing along the depth of the well to obtain a thickness profile; logging temperature along the depth of the well to obtain a temperature log; logging sound frequency along the depth of the well to obtain a noise log; determining the location of the damage by identifying a depth in the thickness profile where the thickness is less than a predetermined thickness threshold; and determining the type of the damage by comparing the temperature log to a geothermal temperature log, and the sound frequency at the damage with a frequency threshold.

2 : The integrated method of claim 1 , wherein the damage is determined to be a leak, when the temperature of the temperature log is constant or decreases relative to the geothermal temperature log with increasing depth along the vicinity of the damage.

3 : The integrated method of claim 1 , wherein the damage is determined to be a leak, when the temperature of the temperature log fluctuates with increasing depth along the vicinity of the damage, and the sound frequency is greater than or equal to the frequency threshold in the vicinity of the damage.

4 : The integrated method of claim 1 , wherein the damage is determined to be corrosion, when the temperature of the temperature log increases relative to the geothermal temperature log with increasing depth along the vicinity of the damage.

5 : The integrated method of claim 1 , wherein the damage is determined to be corrosion, when the temperature of the temperature log fluctuates with increasing depth along the vicinity of the damage, and the sound frequency is less than the frequency threshold in the vicinity of the damage.

6 : The integrated method of claim 1 , wherein the damage has at least one crack and the method further comprises determining the depth of the at least one crack by measuring amplitude and travel time of reflected sonic signals in the vicinity of the damage.

7 : The integrated method of claim 1 , wherein the thickness is logged by a thickness measurement device selected from the group consisting of a mechanical caliper, an ultrasonic caliper, an electromagnetic caliper, and a flux-leakage tool.

8 : The integrated method of claim 1 , wherein the temperature is logged by at least one temperature sensor selected from the group consisting of a thermocouple, a resistance temperature detector, a thermistor, and a silicon bandgap temperature sensor.

9 : The integrated method of claim 1 , wherein the noise log further comprises sound level, and the sound level and the sound frequency in the noise log are obtained by a submersible noise detector.

10 : The integrated method of claim 1 , wherein the well further comprises tubing which is located concentrically inside the casing, and the method determines the location and type of a damage in the tubing.

11 : The integrated method of claim 1 , wherein the casing is selected from the group consisting of a conductor casing, a surface casing, an intermediate casing, and a production casing.

12 : The integrated method of claim 1 , which is a rigless operation.

13 : The integrated method of claim 1 , wherein a subterranean formation surrounds the well, and the subterranean formation comprises one or more of natural gas, oil, gas condensate, and water.

14 : A non-transitory computer readable medium having instructions stored therein that, when executed by a computer, cause the computer to perform an integrated method of determining location and type of a damage in a casing of a well, the integrated method comprising:
logging thickness of the casing along the depth of the well to obtain a thickness profile; logging temperature along the depth of the well to obtain a temperature log; logging sound frequency along the depth of the well to obtain a noise log; determining the location of the damage by identifying a depth in the thickness profile where the thickness is less than a predetermined thickness threshold; and determining the type of the damage by comparing the temperature log to a geothermal temperature log, and the sound frequency at the damage with a frequency threshold.

15 : The non-transitory computer readable medium of claim 14 , wherein the damage is determined to be a leak, when the temperature of the temperature log is constant or decreases relative to the geothermal temperature log with increasing depth along the vicinity of the damage.

16 : The non-transitory computer readable medium of claim 14 , wherein the damage is determined to be a leak, when the temperature of the temperature log fluctuates with increasing depth along the vicinity of the damage, and the sound frequency is greater than or equal to the frequency threshold in the vicinity of the damage.

17 : The non-transitory computer readable medium of claim 14 , wherein the damage is determined to be corrosion, when the temperature of the temperature log increases relative to the geothermal temperature log with increasing depth along the vicinity of the damage.

18 : The non-transitory computer readable medium of claim 14 , wherein the damage is determined to be corrosion, when the temperature of the temperature log fluctuates with increasing depth along the vicinity of the damage, and the sound frequency is less than the frequency threshold in the vicinity of the damage.

19 : The non-transitory computer readable medium of claim 14 , wherein the damage has at least one crack and the method further comprises determining the depth of the at least one crack by measuring amplitude and travel time of reflected sonic signals in the vicinity of the damage.

20 : The non-transitory computer readable medium of claim 14 , wherein the thickness profile, the temperature log, and the noise log are measured in parallel in real-time.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al-Hussain Ali Musa
• Hossain M Enamul

Classifications

• G01N17/04

  Corrosion probes · CPC title

• G01B21/08 Primary

  for measuring thickness · CPC title

• E21B47/1005 Primary

  Fixed Constructions · mapped topic

• E21B47/101

  Fixed Constructions · mapped topic

• E21B47/065

  Fixed Constructions · mapped topic