top the oil sand的意思|示意

Oil sand mining began in Alberta in 1967.That first mine is closest to the Athabasca River in the top image (1984).

阿伯达省的油砂矿开始于1967年，最早的矿井是上图（1984年）中离阿萨巴斯卡河最近的那个。

The technical measure of sand out on top and resin sand at tail is suggested and for those Wells of oil zone developing much better but the physiognomy being complex, horizontal well can be exploited.

建议采取端部脱砂尾追树脂砂工艺措施，对于油层发育较好，但地势复杂的井，可以探索水平井开发。