Recoverable reserves Definition Recoverable reserves is usually defined as the proportion of resources, here oil and gas, that can be technically, economically and legally possible to extract. The recoverable reserves may also be called proven reserves. Comments The recoverable reserves may be far different from the total resources called total Petroleum Initially-In-Place (PIIP). This Petroleum Initially-In-Place (PIIP) is an estimation resulting from exploration campaign and geological calculations. At the stage of the evaluation of the Petroleum Initially-In-Place (PIIP), no provisions are made because of the technology requested to extract it or its economical viability. The Petroleum Initially-In-Place (PIIP) is just reflecting that a certain quantity of hydrocarbons is laying in a given reservoir and under any state. Then the question comes if the state under which this hydrocarbon has been identified makes it recoverable or unrecoverable. The resources are declared recoverable reserves if they may be developed with reasonable certainty from a given date under current economic conditions, operating methods, and government regulations. Then with the oil and gas field moving on from exploration into development phase and production, these recoverable reserves will be categorized in developed and undeveloped. In some cases a share of the probable reserves may also be considered as recoverable reserves if once the presence of these probable reserves is confirmed by further exploration, it is admitted with high probability that the state of these probable reserves is similar to the already proven reserves and therefore recoverable. Possible reserves cannot be considered as recoverable reserves due to the accumulation of uncertainty about the nature of these reserves at a given date. By definition the reserve have been categorized between: - 1P reserves = proven reserves (both proved developed reserves + proved undeveloped reserves) - 2P reserves = 1P (proven reserves) + probable reserves, hence proved AND probable. - 3P reserves = the sum of 2P (proven reserves + probable reserves) + possible reserves, all 3Ps proven AND probable AND possible. These definitions are well-known and recognized for conventional oil and gas, but the development of unconventional resources (Extra heavy crude oil, Tight oil, Tight gas, shale gas, Oil sand, etc...) requested more accurate definitions since the estimation of recoverable reserves is attached to the notion of certainty or probability of recovery according to number of provisions. Canada being the country with the largest unconventional resources went through the exercise to go deeper in the details of the provisions to be made for the calculation of recoverable resources and published in 2002 in the Canadian Oil and Gas Evaluation Handbook (COGEH). The COGEH itself can be obtained from the Petroleum Society of the Canadian Institute of Mining, Metallurgy and Petroleum, Calgary This document proposes the table below to classify the resources between recoverable reserves and unrecoverable according to the degree of uncertainty of their related technical and commercial provisions. Then the legal contingencies must also be considered as having a major impact on the unconventional resources to declare them recoverable or unrecoverable as for example with shale gas, allowed in USA and banned in most of European countries.
Regasification Definition: Regasification is the physical process by which liquefied natural gas (LNG) is heated to be returned into its gaseous state. Comments The natural gas is liquefied to facilitate its transportation as its volume reduces by 600 times from its gaseous state. To be liquefied, the natural gas needs to be cooled down to -161 degrees Celsius to condensate into a liquid which is colorless, odorless, non-corrosive and non-toxic. It is then called liquefied natural gas (LNG) and characterized as a cryogenic liquid. Once liquefied, the LNG may be easier to transport and store as long as it is maintained at this low temperature of -163°C as LNG undergoes a rapid transition to vapor especially if spilled on water. Considering that the volume of the LNG instantly expands 600 times any default in the refrigeration or in the regasification process shall result in a physical explosion called Rapid Phase Transition (RPT). The storage, transportation and regasification of LNG poses a hazard for structures and people potentially exposed. This explosion does not involve combustion. When LNG is spilled on water, heat is transferred from the water to the LNG. This results in a rapid transformation of liquid to gas releasing a large amount of energy. This risk is carefully considered in the design of the LNG carriers since most of the LNG is transported around the globe by dedicated vessels. In pratice the regasification is performed in gradually warming the gas back up to a temperature of over 0°C. It is done under high pressures of 60 to 100 bar, usually in a series of seawater percolation heat exchangers, the most energy efficient technique when water of the right quality is available. An alternative method is to burn some of the natural gas to provide heat. Once LNG carriers have berthed and offloaded their cargo into LNG import terminal, the liquefied natural gas is returned to cryogenic storage tanks, usually varying in capacity from 100,000 to 160,000 cubic meters, depending on the site, where it is kept at a temperature of -163°C prior to regasification. On its way out of the LNG terminal through pipelines and distribution network, the natural gas undergoes any treatment processes needed to bring its specifications in line with regulatory and end user requirements. Its heating value, for example, may be tweaked by altering nitrogen, butane or propane content or blending it with other gases. These operations of liquefaction and regasification of LNG must not be confused with LPG. The LPGs are liquefied petroleum gas, mostly propane, propylene, butane, or butylene which are liquefied by a simple compression at atmospheric temperature. LPGs may be stored and transported in armored tanks at atmospheric temperature without additional refrigeration. The LPGs regasification is proceeded smoothly just in decreasing the pressure when released from the reservoir for use. LPGs are commonly used in domestic applications and require normal safety attention.
Rubber Definition: Rubber is the common name given to Styrene Butadiene or Styrene Butadiene Rubber (SBR). Comments: Produced out of the butadiene, the C4 Olefins family, either by fraction distillation either as byproducts of the Ethylene in the steam cracker, the Rubber is mostly used because of its adhesive performances for tyres, sealants, sho soles, coatings.