The document describes the process for drilling and extracting oil from underground reservoirs: 1) A surface hole is drilled using a drill bit and drill pipes to circulate mud and bring cuttings to the surface, adding sections as it gets deeper. 2) Once the desired depth is reached, casing is run and cemented to prevent hole collapse, then tests like logging and drilling determine if an oil reservoir is present. 3) If oil is detected, the well is completed by perforating the casing, installing a tubing and packer system to control flow to the surface.

1. 1) Dig up a surface hole from starter hole downwards. Steps involved are as follows:
a) Place the drill bit, collar and drill pipe in the hole
b) Attach the Kelly and turntable to drill
c) As the drilling progresses, circulate mud through the pipe and out from the bit to bring
the rock cuttings out of the hole.
d) As the hole gets deeper, add new section (joints)
e) Remove the bit, collar and pipe when the desired depth is achieved.
2) Run and cement the casing once the pre depth is achieved. The casing pipe prevents the
hole from collapsing on itself. Casing pipe has spacers around it to help maintain the central
position in the hole.
3) Cement is pumped down the casing pipe (using a bottom plug, a cement slurry, a top plug,
drill mud)
4) Pressure from the drill mud causes the slurry to move through the casing and fill the space
between casing and hole.
5) Allow the cement to harden and check it’s properties for hardness, alignment and proper
seal.
Testing for Oil: when the rock cuttings from mud reveal the oil sand from the reservoir rock, we have
reached the desired depth and to confirm the same there are few tests to be carried out.
1) Well logging – lowering electrical and gas sensors into the hole to take measurements of the
rock formations
2) Drill-stem testing- lowering a device to measure the pressure and ascertain if reservoir rock
is reached or not
3) Core samples–taking samples of rock for identifying the properties
Well Completion: if oil is detected then well is completed to allow oil to flow through casing in a
controlled manner.
1) A perforating gun is lowered into the well to create holes in the casing for oil to flow.
2) After the casing is perforated tubing is run into the hole as a conduit for gas and oil to flow
up.
3) Packer is run down the outside of tubing to set it expands to form a seal around the outside
of tubing.
4) A multi valve structure called Christmas Tree is connected to the top of tubing and
cemented to the top of casing. The tree helps to control the flow of oil from the well.
Oil Production:
1) For limestone reservoir rock, acid is pumped down the well and out of perforations.
2) For sandstone reservoir rock, a specially blended fluid containing proppants (sand,
aluminium pellets, walnut shells) is pushed down. The pressure from the fluid makes small
fractures in the sandstone that allows oil to flow into the well.
3) Once oil starts flowing, rig is removed and production equipment is placed to extract oil
from well.

2. Oil Extraction:
1) A pump is put on the well head. The electric motor drives a gear box that moves the lever.
2) The lever pushes and pulls a polishing rod up and down.
3) The polishing rod is attached to a sucker rod which in turn is attached to a pump. The system
forces the pump up and down creating a suction to draw up the oil.
4) If oil is too heavy to flow then a second hole is drilled into the reservoir and injects steam
under pressure. The heat from the steam thins the oil and the pressure pushes it up the
well. The process is called enhanced oil recovery.
Offshore Oil Drilling:
Sonic equipment is used to identify the drilling sites. Then a MODU (mobile offshore drilling
unit) is used to dig well.
Four types of MODU available:
1)
2)
3)
4)
Submersible MODU
Jackup
Drill ships
Semi submersibles
FLOWBACK:
Source Data will be time based. Unit conversions to be verified.
Two trigger values:
Pump pressure and flow in
Triggers are criteria which cause plotting to stop. When the trigger conditions return to normal,
plotting will restart from the zero position with a new line and new colour subject to line cycling.
Historical data specifies the number of past minutes to retrieve data for when plotting. Default 10,
max 50.
Data retrieval will stop when the duration is reached or there is no more data to retrieve.