Abstract

There is disclosed a method for testing the pressure integrity of a barrier in an annulus outside a pipe string in a wellbore, the method including the steps of: - establishing a fluid connection between an inside of the pipe string and an annulus out-side the pipe string at a first position and second positions in the wellbore, the second position being offset from the first position along the axial direction of the wellbore; - establishing a temporary barrier between the fluid connections at the first and second positions in the wellbore; - establishing a pressure differential across the temporary barrier; - releasing a tracer from below the temporary barrier; and - sniffing for tracer above the temporary barrier to verify a leakage through the temporary barrier and/or the barrier in the annulus. There is also disclosed a tool for executing such a method.

IPC Classes  ?

• E21B 47/098 - Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes using impression packers, e.g. to detect recesses or perforations
• E21B 47/117 - Detecting leaks, e.g. from tubing, by pressure testing
• E21B 47/11 - Locating fluid leaks, intrusions or movements using radioactivity
• E21B 47/005 - Monitoring or checking of cementation quality or level

Abstract

A system (1') for testing the integrity of a well barrier (2), the system (1') comprising: - a well (10) including a wellbore (4) and a upper wellbore termination means (8), such as a wellhead; - a mud circulation system (70) and/or a mud conditioning system (80) comprising means for transporting, cleaning or storing mud outside said wellbore (4); - a barrier (2) provided in the wellbore (4), the barrier having an upstream side (12) below the barrier (2) and a downstream side (14) above the barrier (2); - a tracer (16); - a storage means (18) for storing said tracer (16), the storage means (18) being provided in a lower part of the barrier (2) and/or below the barrier (2) in the well (10); and - a release mechanism for releasing the tracer (16) from the storage means (18), wherein the system (1') further comprises a detector (20) for detecting tracer (16) that has leaked through the barrier (2) and into said mud (5), the detector (20) being arranged above the wellbore (4). There is also described a method for testing the integrity of a well barrier (2) by means of such a system (1')

IPC Classes  ?

• E21B 47/117 - Detecting leaks, e.g. from tubing, by pressure testing
• E21B 47/11 - Locating fluid leaks, intrusions or movements using radioactivity
• G01M 3/28 - Investigating fluid tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for valves