LCA is a technique to assess the environmental aspects and potential impacts associated

with a product, process, or service, by: Compiling an inventory of relevant energy and material

inputs and environmental releases. Evaluating the potential environmental impacts associated

with identified inputs and releases.

Crude oil development and production in modern country include three distinct phases:

primary, secondary, and tertiary (or enhanced) recovery. During primary recovery only about 10

percent of a reservoir's original oil in place is typically produced. Secondary recovery techniques

extend a field's productive life generally by injecting water or gas to displace oil and drive it to a

production wellbore, resulting in the recovery of 20 to 40 percent of the original oil in place.

However, with much of the easy-to-produce oil already recovered from U.S. oil fields, producers

have attempted several tertiary, or enhanced oil recovery (EOR), techniques that offer prospects

for ultimately producing 30 to 60 percent, or more, of the reservoir's original oil in place.

By cradle to grave assessment:

Water injection: Seawater treated and to be pump into reservoir where the density of

water more than density of crude will lift up the crude from the reservoir. 60-70% of the

seawater will be pump back to the sea and 40-30% will be pumped to the reservoir. Since

seawater is easily available (70% of the earth consists of seawater) it is very economic and

environmental friendly. The reservoir will not be damaged by chemicals since the treated

seawater is de-mineralized and deionized. The problem rise when the seawater fills up the pores

in the soil makes the soil prone to move and makes the soil unstable. Impact the structural

integrity as a whole.

CO2 flooding: CO2 flooding is another method on recovering hydrocarbon. CO2

captured via n Carbon Capture & Sequestration Enhanced Oil Recovery (CCS EOR), carbon

dioxide is injected into an oil field to recover oil that is often never recovered using more

traditional methods. Since CO2 is a stable molecule, when it injected to the reservoir, it will not

impact the crude in terms of their properties. But if the crude is sour (high H2S), it may cause

environmental problem such as release of SOx to the atmosphere when the crude is in the

processing stage. It may impact the groundwater as well and costly to treat high content of CO2

inside the water aquifer.

Understanding of each stages of processing, input (raw material) to its output (products + waste)

is very crucial to provide mitigation and cost before proceed with the investment and technology

used for once process or as a whole.