Besides eliminating WOC time, Cellar Tech’s proprietary surface casing hanger system also has a proven track record of helping to prevent shallow gas migration.
Cellar Tech’s Surface Casing Hanger lands the last joint of surface casing on the structural base plate of the cellar. Therefore all the weight of the surface casing, wellhead, BOP, and drill out forces are supported by the cellar’s structural base plate and not by the surface casing’s cement sheath. Because the surface casing’s cement sheath remains non-load bearing through its entire compressive strength development it is allowed to set-up properly. Also drilling out is a violent process, however since the casing is suspended from surface on the hanger, drill out forces are less prone to damage the cement sheath.
Pilot tests of seventy eight wells in the Marcellus Shale our Surface Casing Hangers were evaluated and compared to a much larger subset of wells. On wells without Cellar Tech Surface Casing Hangers 9% showed bubbles in the cellar that were determined to be outside the surface casing. Wells that used Cellar Tech’s Surface Casing Hangers showed no gas observed with the exception of four that were all on one pad. Upon further investigation, it was discovered that the four wells that showed gas migration had been drilled through a double mine void. Since the pilot tests, hundreds of Cellar Tech Surface Casing Hangers have been used in the Marcellus with E&P companies reporting a six to thirteen hour savings per well and no shallow gas migration.
Additional benefits can also be capitalized on when using Cellar Tech’s Surface Casing Hanger to include an elimination of WOC time. E&P companies who use our Surface Casing Hangers have also stopped certain costly practices that were carried out in the past to try and improve the surface casing’s cement sheath. In one case, a Marcellus operator reported a $12,000 savings per well since they have stopped rotating their casing to help improve the surface casing cement sheath’s integrity. Cellar Tech’s Surface Casing Hanger system alone will not guarantee a good cement job but the system does add to cement jobs by allowing compressive strength to be fully reached without any outside forces acting on the cement sheath. Savings to E&P companies are captured by being able to use standard slurries but still achieve a good cement job, elimination of certain procedures used in the past to improve cement integrity, and elimination of WOC time.
If you would like more information about Cellar Tech’s Surface Casing Hanger, or any other products, please contact us today.