Oil companies need offshore platforms primarily because the oil or natural gas the companies extract from the ocean floor has to be processed before pumps can be used to move the substances ashore.
Topic
Why offshore oil platforms exist and how researchers are redesigning two pump types in hopes of reducing or eliminating them.
Framework
Highlight Noteworthy. The author explains a current limitation of the technology and walks through two alternatives in development.
Main Point
Platforms exist because crude must be processed before pumps can move it ashore; researchers are redesigning positive-displacement and centrifugal pumps so that crude could be moved directly without on-platform processing — potentially eliminating platforms.
P1: Why platforms exist; what the new pumps would do
Crude must be processed before pumps can carry it ashore — that's why platforms are needed. Processing on a platform is dangerous, so researchers are redesigning two pump types to handle unprocessed crude. The natural pressure of crude only brings it to the platform; getting it to shore would require pumps that can boost pressure even when crude shifts unpredictably between liquid, gas, and solid. Surges in gas content cause loss of pump head and stop pumps from working consistently.
P2: Two pumps
The positive-displacement pump (single or twin screw) handles shifts in liquid/gas ratio but requires expensive corrosion-resistant materials. The centrifugal pump uses a rotating impeller; it's well-tested but its impeller separates gas from oil, causing significant head reduction.
P3: Where research is heading
Researchers are trying to reduce the cost of the positive-displacement pump and make the centrifugal pump more gas-tolerant. Some are also adapting either pump for underwater use, so crude could move directly from sea bottom to onshore processing — eliminating platforms.