**Secondary Recovery Techniques**- **a)** are used to coax more oil out of a drilled hole.- **b)** include the use of steam to make oil more viscous.- **c)** usually enable drillers to get almost 100% of the oil out of the ground.- **d)** include sealing fractures in the rock to concentrate oil in pockets called traps. **Drilling Mud****Question Q009:** Drilling mud Select the correct statement about drilling mud:a) is a slurry of water and sand.b) is created when the drill bit scratches and gouges out the rock.c) is used to cool the drill bit and to flush rock cuttings up and out of the drill hole.d) decreases the surface tension of the oil in the drill hole and can sometimes cause gushers.

Q010 Secondary recovery techniques: Secondary Extraction includes the recovery of oil after natural forces does not further drive oil to the surface. In Secondary recovery water and gas is injected, oil is displaced and finally derived on the surface. In secondary stage external fluids such as gas or water is introduced in the reservoir. The purpose of this secondary recovery is to transfer oil towards the wellbore. a) are used to coax more oil out of a drilled hole. This option is false as the secondary extraction enables the drillers to get more oil after simple pumping of oil. b) include the use of steam to make oil more viscous. This option is also false. c) usually enable drillers to get almost 100% of the oil out of the ground. This option is correct as the purpose of the secondary recovery is to displace oil towards the wellbore. d) include sealing fractures in the rock to concentrate oil in pockets called traps. This option is also wrong. The secondary recovery techniques include the method which removes oil from a reservoir after the natural methods have been exhausted. Therefore, the option (C) is correct for the secondary recovery techniques.Q009 Drilling mud also called drilling fluids is a heavy, viscous mixtures of natural and manmade chemicals used in oil drilling processes. The drilling mud is used to transport rock cuttings to the surface and also is used to lubricate and cool the drill bit.a) is a slurry of water and sand. This option is wrong as the drilling mud is a viscous mixture of natural and manmade chemicals. b) is created when the drill bit scratches and gouges out the rock. This option is also wrong as the drilling mud is not created there but is actually pumped down from the surface. c) is used to cool the drill bit and to flush rock cuttings up and out of the drill hole. This option is right as the drilling mud is used to transport rock cuttings to the surface and also used to lubricate and cool the drill bit. d) decreases the surface tension of the oil in the drill hole and can sometimes cause gushers. This option is wrong as the drilling mud is used to transfer the rock cuttings to the surface and also for lubrication and cooling purpose of the drilling bit. Therefore option (C) is correct.