Deep resistivity “turnover” effect at oil generation “peak” in the Woodford Shale, Anadarko Basin, USA

The Devonian Woodford Shale in the Anadarko Basin is a highly organic, hydrocarbon source rock. Accurate values of vitrinite reflectance (Ro) present in the Woodford Shale penetrated by 52 control wells were measured directly. These vitrinite reflectance values, when plotted against borehole resistivity for the middle member of the Woodford Shale in the wells, display a rarely reported finding that deep resistivity readings decrease as Ro increases when Ro is greater than 0.90%. This phenomenon may be attributed to that aromatic and resin compounds containing conjugated pi bonds generated within source rocks are more electrically conductive than aliphatic compounds. And aromatic and resin fractions were generated more than aliphatic fraction when source rock maturity further increases beyond oil peak. The finding of the relationship between deep resistivity and Ro may re-investigate the previously found linear relationship between source rock formation and aid to unconventional play exploration.

Effect of maturity stage on the chemical composition of argan fruit pulp

Argan tree, a species endemic to Southern Morroco, is well known for its kernel oil used in cosmetics and health-food, but the corresponding pulp attracted less interest from researchers and little is known about its chemical composition and evolution during maturation. The pulp of argan fruits monthly harvested during the ripening period based on fruit color (April to July), was analyzed. With progressing ripeness various changes were observed in the chemical composition, such as (i) a four-fold increase of total soluble sugars content (glucose, fructose and saccharose), and of Fe (75–165 ppm), but also (ii) a drop of many components, such as proteins (10.1–6.4%), and cell wall polymers, lignin (14.9–5.9%) and hemicellulose and cellulose. Hexane-soluble compounds found in substantial amount (10.7% in April) also decreased with time: the pulp oil peak (8.3%) was in April and June, and that of polyisoprene in June (3.6%). Therefore the stage of maturity (harvest date) is to be considered, without affecting the quality of the argan oil.

A Model for the Optimal Recovery of Multiple Substances from Waste Water with a Focus on Phosphate

In recent times, the issue of a “Phosphate Peak” has entered the academic debate and it is widely present in social media. Arguments in favour and against are similar to those mentioned in the much earlier debate on the “Oil Peak”. However, whereas the “Oil Peak” is supply driven, the “Phosphate Peak”, if at all, is demand driven. In contrast with oil, most of which is chemically transformed in CO2, vapor and other constituting elements, phosphate is not “consumed” during its primary use as a fertilizer. Hence, whilst phosphate rock, from which phosphate is mined, is a depletable resource, phosphate itself is potentially recyclable and re-usable. Research on the technologies for such a recovery is manifold and, specifically, efforts are spent on waste water as a source of phosphate. This, if successful, could lead to a changing perception of waste water treatment plants as a set of backstop technologies to eliminate an environmental problem into a “secondary liquid mine” from which phosphate, but not only phosphate, could be extracted for re-use. Hence, for that purpose, an economic model of efficient extraction of phosphate and other elements from waste water in a waste water treatment plant could give guidance to operators. This paper presents such a model describing the optimal simultaneous extraction of several elements, including phosphate, from a “secondary liquid mine”. The elements are assumed to be present in given proportions (ratios) in this “mine” and the model shows that these ratios have an impact on the optimal extraction path and on resulting “implicit” shadow pricing rules to be adopted by the waste water treatment plant operator.