The answer: wells that drill vertically down to the shalebed, then make a gradual 90-degree horizontal turn through the shale deposit.
目前，科学家提出了解决方案——先垂直钻探至页岩床位置，然后以90度水平地钻探页岩沉积层。
2
The fourth oil shalebed developed in lacustrine bog distributes unsteadily with small thickness. It is belong to the oil shale of middle ash and oil yield.
形成于湖沼相的油四层厚度较小，平面上分布不稳定，含油率较高，属中灰分中含油率的油页岩。
3
Nor is shale gas the only new sort of reserve: "tight gas" in sandstones and coal-bed methane (the sort of gas that used to kill canaries down mines) are also promising.