Because there is casing damage in the oil shale layer of many Wells. It is particularly important for us to study the mechanisms and influencing factors about the casing damage of this layer.

油页岩层是发生大面积套损的主要岩层，研究该岩层套损发生机理及影响因素显得尤为重要。

youdao

The local geology favours the retention of contaminants by ion-exchange processes within the clay-rich soils and the shale layer underlying the burial site.

当地的地质条件有利于污染物的滞留，通过埋藏点之下的富粘土土壤和页岩层中的离子交换过程而进行。

youdao

He says the Bakken has a layer of nearly impermeable shale that sits above the oil-bearing reservoirs.

FORBES: Focus

The entire city of Fort Worth sits over a gas dense layer of black rock called the Barnett Shale that only recently became possible to access.

NPR: Drilling for Gas in Dallas-Fort Worth

The problem was that (gas) was locked in shale, the extremely dense layer of rock under Dallas and Forth Worth.

FORBES: Move up http://i.forbesimg.com t Move down