What Exactly is “Loss of Circulation”?

Penn Live published a piece by Bill Godsey, owner and president of Geo Logic Environmental Services and former geologist for the Texas Railroad Commission, focusing on the development of the Mariner East 2 Pipeline in Pennsylvania and elucidating on the construction process therein.

Godsey explains that one thing that has been reported on in recent news cycles on the construction process is the occurrence of “loss of circulation” – But, what exactly does this mean?

Godsey details that “According to DEP and the pipeline construction company, “loss of circulation” is an “indicator of drilling fluid migrating out of the borehole into the ground water.” It cannot be observed from the surface because it’s all happening underground. This is a common occurrence during the pipeline construction known as horizontal directional drilling (HDD). This kind of drilling is the most up-to-date and safest-known method for constructing underground pipelines. It is the best option for minimizing chances of water contamination, though of course no method can possibly be 100 percent accident proof. It requires mud containing non-toxic bentonite — which will not cause any long-term harm to the environment — during construction.”

Godsey concludes that loss of circulation is a “common, predictable and non-threatening mishap” that pipeline companies are well prepared for.