1.   By the time oil prices recovered and a sustained drilling boom took off, the pool of skilled labor had largely evaporated.

2.   In addition, a drilling boom increased demand for its financing services that serve oil companies.

3.   Meanwhile, high prices triggered an exploration and drilling boom.

4.   Now another drilling boom is underway, and rigs are in short supply again.

5.   The drilling boom continues amid unchanged global oil prices and U.S. natural gas prices that continue to lag behind a year ago.

6.   The drilling boom is spurring demand for offshore oil production platforms, which Unifab helps build.

7.   The key, they said, is that the drilling boom is not being fueled by a spike in the price of oil and gas.

8.   Their shares surged over the last two years as a drilling boom prompted by technological improvements cut the price of finding oil.

9.   Their shares surged over the last two years because of drilling boom prompted by technological improvements that cut the price of finding oil.

10.   Their shares surged over the last two years as technological improvements cut the price of finding oil, prompting a drilling boom.