I’ve just returned from the annual Offshore Technologies Conference in Houston, Texas.
Texas is known for BIG and this event was no exception: Some 40,000 people from around the world were checking out some of the largest single hunks of steel I have ever seen – from floating drill platforms and tender boats to humongous deck fittings and valve stands. Hundreds of exhibitors were hawking their wares and services, all focused on the gargantuan global business of offshore petroleum extraction.
This whole field is new to me so there was much to learn. Germaine to the current tragedy in the Gulf of Mexico is that there is quite a disparity between reservoir pressures around the world, and thus the array of equipment to deal with the varying conditions.
For example the reservoirs off Brazil are running a mere 1000 psi – necessitating booster pumps for “assisted lift.” (The water pressure at the 2500’ well depth is ~1000 psi so the pumps have to overcome the water pressure to bring up the oil.)
On the other hand the Gulf of Mexico reservoirs can run 20,000 – 30,000 psi, so throttling back the flow is the challenge. Even at 5000’ well depth (such as the Deepwater Horizon) the water pressure is only ~2000 psi – so the well pressure “overburden” is still really high and can easily jet the oil and gas up to the surface.
The equipment that handles these pressures is likely to be noisy – hence our interest. I spoke with Dave Spelling from Cameron about the choke valve they use to meter the wellhead. It is made out of super-hard tungsten carbide to keep erosion in check. But blasting 30,000 psi of sand, oil, gas, and water through a set of small orifices not larger than 6” is bound to roar a bit.
Dave told me that they are just now starting to fit sensors on the choke valves; accelerometers, thermocouples, and pH sensors to give them an idea about environmental and wear conditions of the equipment.
Of course we would like to measure the noise. If these deepwater, high pressure wells are as loud as we think they are, the ocean noise problems will only increase with the expansion offshore fossil fuel operations. It would be nice to know sooner than later, because mitigation for flow noise is not that complicated; some of these problems could be solved before they really start compromising marine bio-acoustic habitat.