They drill down to the shale, then go sideways and inject high-pressure water, sand or other material into the rock.
当钻到页岩时，从侧面将高压水、沙子和其它东西注入页岩内。
According to the nature, Guangxi limestone is separated into three types: pure limestone, siliceous limestone, mixed sand shale or limestone of igneous rock.
广西的石灰岩按性质可分为纯质石灰岩、夹硅质石灰岩、夹砂页岩或火成岩的石灰岩三种类型。
Wudaoliang group is grayish - white, yellow - grey, dark - grey ash rock, which interbeded with the conglomerate, sandstone, a little amount mudstone, oil shale with unconsolidated sand mud rock.
五道梁群以灰白色、灰黄色灰岩为主，含有砾岩、砂岩，夹有少量泥岩、油页岩和未固结砂泥沉积。
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