Nyob ntawm lawv txoj haujlwm, kev tsim kho tshuab tuaj yeem muab faib ua pawg hauv qab no: kev khawb, txoj kev, drilling, pawg tsav tsheb, kev txhawb nqa, vov tsev, thiab cov tshuab ua tiav, cov tshuab ua haujlwm nrog cov pob zeb, thiab cov tshuab ua haujlwm npaj ua haujlwm.