Quantitative characterization of horizontal well production performance with multiple indicators: a case study on the Weiyuan shale gas field in the Sichuan Basin, China

To quantitatively characterize the horizontal shale gas well productivity and identify the dominant productivity factors in the Weiyuan Shale Gas Field,Sichuan Basin,a practical productivity method involving multiple indicators was proposed to analyze the production performance of 150 horizontal wells.The normalized test production,flowback ratio,first-year initial production and estimated/expected ultimate recovery(EUR)were introduced to estimate the well productivity in different production stages.The correlation between these four indicators was determined to reveal their effects on production performance forecasts.In addition,the dominant productivity factors in the present stage were identified to provide guidance for production performance enhancement.Research indicates that favorable linear relations exist between the normalized test production,first-year initial production and EUR.The normalized test production is regarded as an important indicator to preliminarily characterize the well productivity in the initial stage.The first-year initial production is the most accurate productivity evaluation indicator after a year.The flowback ratio is a supplementary indicator that qualitatively represents the well productivity and fracturing performance.The well productivity is greatly dependent on the lateral target interval,drilling length of Longmaxi1_(1)^(1)(LM1_(1)^(1))and wellbore integrity.The first-year recovery degree of EUR is 24%–58%with a P50 value of 35%.

A re-evaluation of the Chaetothyriales using criteria of comparative biology

Chaetothyriales is an ascomycetous order within Eurotiomycetes.The order is particularly known through the black yeasts and filamentous relatives that cause opportunistic infections in humans.All species in the order are consistently melanized.Ecology and habitats of species are highly diverse,and often rather extreme in terms of exposition and toxicity.Families are defined on the basis of evolutionary history,which is reconstructed by time of divergence and concepts of comparative biology using stochastical character mapping and a multi-rate Brownian motion model to reconstruct ecological ancestral character states.Ancestry is hypothesized to be with a rock-inhabiting life style.Ecological disparity increased significantly in late Jurassic,probably due to expansion of cytochromes followed by colonization of vacant ecospaces.Dramatic diversification took place subsequently,but at a low level of innovation resulting in strong niche conservatism for extant taxa.Families are ecologically different in degrees of specialization.One of the clades has adapted ant domatia,which are rich in hydrocarbons.In derived families,similar processes have enabled survival in domesticated environments rich in creosote and toxic hydrocarbons,and this ability might also explain the pronounced infectious ability of vertebrate hosts observed in these families.Conventional systems of morphological classification poorly correspond with recent phylogenetic data.Species are hypothesized to have low competitive ability against neighboring microbes,which interferes with their laboratory isolation on routine media.The dataset is unbalanced in that a large part of the extant biodiversity has not been analyzed by molecular methods,novel taxonomic entities being introduced at a regular pace.Our study comprises all available species sequenced to date for LSU and ITS,and a nomenclatural overview is provided.A limited number of species could not be assigned to any extant family.