D rilling Once initial exploration has discovered likely oil or gas deposits the next stage is to start drilling . That is the only sure way to find out if the prospect contains oil and gas . Even if the hole is dry a lot of information can be gained from the well . The well is drilled in sections of decreasing diameter . | Fig . 5 | The very first head starting drilling is bigger than the one coming after . | Fig . 2 | Once the first
section is drilled , cement is pumped around the steel well casing ( which surrounds the drill pipe ) to fill the space between it and the wall of the borehole . This ensures the hole does not collapse . This process is repeated until the reservoir is reached . Some oils are heavy and cannot reach the surface on its own so they drill another well and inject steam into it thus making the oil thinner and increasing the pressure in the well .
Preventing “ blow-outs ” drilling technology had
6
TThe become so good since the first field and demand for oil is irresistible . Oil companies had sailed off the continental shelf into deeper waters . Temperature on the seafloor is near freezing while the oil reservoir can reach 400 degrees Fahrenheit . Pockets of explosive methane gas and hydrates , frozen but unstable , increasing the risk of blowout . The biggest oil spill in the history happened just last year , 2010 The Macondo Well in Gulf of Mexico where one of the world ’ s most advanced rig , the $ 560 – million Deepwater Horizon burned after the April 20 well blowout and sank with the loss of 11 lives .
The weight of the drilling fluid acts as the first line of well control by keeping underground pressures Drilling is the only sure way in check . If an influx to find out if the prospect of pressurized oil or contains oil and gas . gas does occur during drilling , well control is maintained through the rig ’ s blowout prevention system . This is a set of hydraulically operated valves and other closure devices ( rams ) which seal off the well , and route the wellbore fluids to specialized pressure controlling equipment . Trained personnel operating this highly reliable equipment minimize the possibility of a “ blowout ”, or an uncontrolled flow of fluids from a well .
7
If there was catastrophic failure and the “ well ” could not be contained , then the oil company would be likely to call in the world ’ s largest Oil Spill Company . This is Oil Spill Response Ltd ( OSRL ) based In the UK and is funded by 70 % of the world ’ s oil producers . Oil Spill Response has responded to over 350 spills in more than 25 countries . It is the only organisation with two Hercules aircraft on permanent stand-by , it has three ADDS Packs ( Aerial Dispersant Delivery System ) and developed the award winning NIMBUS dispersant delivery device . The company has 24 hour and 365 day obligations to its members at a time of an incident where they will respond globally to any oil spill . Responsible oil companies have contingency plans in place for such events which include trained personnel , oil spill equipment onshore and offshore on vessels and then OSRL to call upon at the time of an unfortunate event . Many oil companies around the world have small teams of first responders trained for these types of incidents and equipment to deploy as a first response till help arrives .
8 www . oilcityghana . com 11