The Industry Challenge:
Well operators often encounter tight spots in the wellbore that impair access to the well that may prevent deployment of artificial lift systems and lead to loss of pressure integrity in the well.
Impression blocks and caliper surveys can be used to gain a better understanding of the shape of the damaged casing; however, the information gained is usually insufficient to design repair programs or modify well designs and operating practices to avoid similar failures in the future.
Well tubing and casing in severe operating environments such as HPHT, thermal, through salt and in subsiding reservoirs are prone to deformations caused by formation movements induced by production operations and by regional tectonic activity.
Large changes in well temperatures between production and work over operations can further impose large thermal stresses on the casing which can lead to deformations.
These deformations can impair well access, preventing well servicing and stimulation in zones below the deformations and can compromise the pressure integrity of the well by damaging tubing and casing connections.
Operators must understand the root cause of the deformations and how the deformations may progress with time to help plan well interventions in damaged wells and to design new well completions to resist these deformations.
How We Help:
C-FER developed a software tool called CalTran™ that uses common multi-finger caliper data from casing inspection surveys to identify local changes in well trajectory that are associated with well deformations.
This can include differentiating between buckling, shear and collapse of the casing to identify the root cause of the deformation.
In addition, conducting repeat logs at different times in the well history can show how the deformation increases with time or in response to specific well operations.
This information can be used by Operators to plan appropriate repair programs, to estimate the remaining operating life of the well and to design new wells and operating procedures to avoid similar problems in future wells.
This ability to track well deformations has also been incorporated in WellXplore which can compare multiple logs from one or more wells to help evaluate field‑wide well deformations which often occur where significant reservoir compaction and surface subsidence exists.