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Wax is a prevalent lubrication material extensively employed in various engineering applications. Understanding the degradation characteristics of the waxy lubrication layer under diverse stress variables and levels is crucial for ensuring system security and reliability. Due to the unclear mechanism governing the degradation of the waxy lubrication layer under different stress variables, existing degradation models are unsuitable for modeling waxy lubrication layer degradation data. To address this challenge, we propose a functional data‐driven method leveraging dense observations of waxy degradation. Through extensive simulations and a case study, we demonstrate the superior performance and effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Shale reservoirs contain petroleum that undergoes losses through oil expulsion and evaporation, with uncertain implications on shale oil reserves and mobility evaluation. This study focuses on understanding the influence of these losses on open‐system pyrolysis, the primary method for assessing shale oil content and mobility. Comprehensive analyses were performed on 26 lacustrine shale samples from the Chang7 Member, encompassing total organic carbon (TOC), programmed pyrolysis, solvent extraction, and gas chromatography–mass spectrometry (GC–MS). The research examines the impact of petroleum losses on petroleum fractions, the oil saturation index (OSI), and multi‐step pyrolysis outcomes. The findings indicate that Chang7 shale with TOC content above 7% experiences more substantial petroleum losses than those with TOC below 7%. Petroleum losses result in significant fractional distillation of crude oil in the shale, leading to the deterioration of shale oil properties and a notable reduction in free oil content in S1, ultimately causing a decline in OSI values. As a result, Chang7 shale with TOC below 7% demonstrates a higher potential for shale oil recovery, whereas Chang7 shale with TOC exceeding 7% should be considered more significant as a hydrocarbon source rock. Moreover, multi‐step pyrolysis is not suitable for assessing petroleum mobility in shale with low free oil content (OSI values below 100 mg/g). This limitation arises from the loss of free low‐boiling components in Chang7 shale, and the currently detected low‐boiling pyrolysis products may predominantly exist in an adsorbed state. [ABSTRACT FROM AUTHOR]

Carbonate cementation is one of the significant tightness factors in Chang 6 reservoir of the western Jiyuan (WJY) area. Based on the observation of core and thin sections, connecting-well profile analysis as well as carbon and oxygen isotope analysis, it is found that ferrocalcite is the main carbonate cements in the Chang 6 reservoir of the WJY area. The single sand body controls the development of carbonate cements macroscopically. Both carbonate cements and calcite veins hold similar diagenetic conditions: the dissolution of plagioclase is the main calcium source and the de-acidification of organic acids is the main carbon source. The diagenetic stage is identified as the mesogenetic A stage. The sedimentary environment is of low salinity. Accordingly, the development model of carbonate cementation in Chang 6 reservoir is summarized into three types: “eggshell pattern,” “cutting pattern,” and “favorable reservoir pattern.” The development degree of carbonate cementation affects the physical properties of reservoir.

Lithologic identification is critical for studying fine - grained sediments, which further elucidates sedimentary environment, and formation. The oil - bearing Chang 7 Section of the Yanchang Formation in Ordos Basin contains thick dark mudstone with a wide distribution, interbedded by siltstone and fine sandstone. The lacustrine fine - grained sedimentary rocks constitute the chief source rock of the Yanchang Formation. On the grounds of fine core description, thin rock slice identification and X - ray diffraction analysis, we proposed a new method based on conventional logging data. This method is using density (DEN) and natural gamma (GR) logging curve intersection and multivariate linear regression analysis of logging curve value and measured mineral content value which is carried out by SPSS software to identify the lithology and the vertical distribution characteristics of fine - grained sedimentary rock of Chang 7 formation in the study area. This method is mainly suitable for lithologic identification of fine - grained sedimentary rocks in lake basin. It not only quantitatively analyses the contents of main minerals and organic matter in fine - grained sedimentary rocks, but also greatly improved the accuracy and universality of using conventional logging data to identify the lithology of fine - grained sedimentary rocks, which provides a reference for the exploration of tight oil.

Post-colonial land tenure reforms in emerging countries have partly aimed at poverty reduction through equitable land access. However, the poverty rate keeps rising in rural and peri-urban settings in Sub-Saharan Africa dominated by agricultural activities. This article reviews land tenure reforms in Mali, from the year 2000 to 2017 regarding poverty alleviation and evaluates their impacts on indigenous smallholder farmers, using multiple linear and logistic regression models and local experts' elicitations. The results indicate that the advent of land titles as the only definitive evidence of land ownership, following the reforms, has generally weakened customary land management. Smallholder farmers face several barriers to obtaining land titles, limiting equity in land access and security. This has paved way for land markets marred by irregularities and resulted in colossal loss of agricultural lands, which are the main source of rural livelihood. Thus, the reforms have not yielded the intended poverty reduction outcomes. The study recommends that land transfers must be authorised by a single institution, represented at the various administrative levels, which issues an authentic and incorruptible document using appropriate technology. Moreover, since pro-poor provisions in the reforms usually lack implementing decrees in Mali, political will is key to achieving equitable land access and security.