Intelligent production optimization method for a low pressure and low productivity shale gas well

Shale gas wells frequently suffer from liquid loading and insufficient formation pressure in the late stage of production.To address this issue,an intelligent production optimization method for low pressure and low productivity shale gas well is proposed.Based on the artificial intelligence algorithms,this method realizes automatic production and monitoring of gas well.The method can forecast the production performance of a single well by using the long short-term memory neural network and then guide gas well production accordingly,to fulfill liquid loading warning and automatic intermittent production.Combined with adjustable nozzle,the method can keep production and pressure of gas wells stable automatically,extend normal production time of shale gas wells,enhance automatic level of well sites,and reach the goal of refined production management by making production regime for each well.Field tests show that wells with production regime optimized by this method increased 15%in estimated ultimate reserve(EUR).Compared with the development mode of drainage after depletion recovery,this method is more economical and can increase and stabilize production effectively,so it has a bright application prospect.

Hydration mechanism of low quality fly ash in cement-based materials

The hydration mechanism of low quality fly ash in cement-based materials was investigated. The hydration heat of the composite cementitious materials was determined by isothermal calorimetry, and the hydration products, quantity, pore structure and morphology were measured by X-ray diffraction(XRD), thermalgravity-differential thermal analysis(TG-DTA), mercury intrusion porosimetry(MIP) and scanning electron microscopy(SEM), respectively. The results indicate that grinding could not only improve the physical properties of the low quality fly ash on particle effect, but also improve hydration properties of the cementitious system from various aspects compared with raw low quality fly ash(RLFA). At the early stage of hydration, the low quanlity fly ash acts as almost inert material; but then at the later stage, high chemical activity, especially for ground low quality fly ash(GLFA), could be observed. It can accelerate the formation of hydration products containing more chemical bonded water, resulting in higher degree of cement hydration, thus denser microstructure and more reasonable pore size distribution, but the hydration heat in total is reduced. It can also delay the induction period, but the accelerating period is shortened and there is little influence on the second exothermic peak.

Use of Low Radioactive Rare-earth Waste for Sewage Treatment

Low radioactive rare earth waste (containing 232 Th,specific activity 5 000 8 000 Bq·kg -1 ) were diluted 20 times by cement,sand and carbide ash and were made into special cement.The radioactivity of this special cement complied with the healthy protect standard for radioactive materials (GB6566 86).Test results showed that this special cement could lower COD,the degradation rate increased as the time went on.In acidic medium,this special cement could remove E Coli effectively.Applying aeration and adding lumps of cement,the degradation of COD versus time complied with Logistic model through fitting by computer.The two “S” curves indicated that aeration and adding lumps of cement had synergistic action on sewage treatment.

Low temperature hydrogen production from water and methanol over Pt/α-MoC catalysts

Subject Code:B03 With the support by the National Natural Science Foundation of China,a collaborative study by the research groups led by Prof.Ma Ding(马丁)from Peking University,Prof.Zhou Wu(周武)from the University of Chinese Academy of Sciences,Prof.Wen Xiaodong(温晓东)from the Institute of

Corrosion Evolution of Low Alloy Steel in Deaerated Bicarbonate Solutions

Corrosion evolution during immersion tests （up to 43 days） of NiCu steel in deaerated 0.1 mol/L bicarbonate solutions was investigated by electrochemical measurements, scanning electron microscopy （SEM） and X-ray diffraction （XRD）. Results show that NiCu steel transformed from the anodic dissolution in the early stage of immersion to a metastable passive state in the final stage as the open-circuit potential value shifted positively, which was aroused by the precipitation of corrosion products. This process was mainly promoted by the trace amount of oxygen. Simultaneously, dominant cathodic reaction transformed from the hydrogen evolution in early stage to reduction processes of corrosion products in later stages. Possible corrosion processes were discussed with the assistance of a corresponding Pourbaix diagram.

Potential of conservation tillage and altered land configuration to improve soil properties,carbon sequestration and productivity of maize based cropping system in eastern Himalayas,India

Poor soil properties especially low soil organic carbon(SOC)and nutrient and water retention capacities are major concern for sustainable agriculture in Himalayas.Field experiments were conducted to assess the effects of six combinations of tillage[conventional tillage(CT)and no-till(NT)]and land configurations[flat bed planting(FB),ridge and furrow planting(RF),and raised bed planting(RB)]on productivity and carbon(C)-sequestration potential of maize[(Zea mays L.)for green-cob in summer]-maize(for grains in rainy season)-field pea[(Pisum sativum L.in winter]cropping system under humid mildtropical climate of Tripura,India.The maize under NT-FB in 2012 and NT-RF in 2013 produced significantly higher green cob yield than that under CT-RF.However,in rainy season,CT produced higher maize grain yield than NT systems.Field pea seed yield was significantly the highest under NT-RB.After two cropping cycles,NT systems had higher available N,P,K and 18.6e31.4%higher soil moisture content after rainy season maize than CT system.The highest SOC-stock(0e30 cm)was observed under NT-FB,whereas,SOC-sequestration rate was maximum under NT-RB(0.85 Mg ha1 year1).Therefore,NT based systems can enhance the productivity and improve SOC-sequestration in cultivated soils of eastern Himalayas.Hence,study recommended adoption of NT-RB/NT-FB to raise maize-maize-field pea system for improving productivity,improving C-sequestration and soil properties in the eastern Himalayas and similar eco-regions elsewhere.

Effects of Nitrogen and Phosphorus Fertilization on Soil pH-Plant Productivity Relationships in Upland Grasslands of Northern Greece

The potential role of soil pH in modulating plant productivity was assessed on the basis of dry mass, harvested in the form of 0.25 m2 quadrats, in two low-productivity upland grasslands of northern Greece subjected to annual factorial nitrogen （N） and phosphorus （P） fertilization （15 g N m-2 year-1 and 10 g P m-2 year-I） over a minimum period of 3 years. It was hypothesized that under these particular conditions, a positive relationship would exist between soil pH and plant productivity and, further, that N or P fertilizer application of a nutrient limited system, would result in a weakening of this positive relationship. A significant positive relationship was confirmed between soil pH and plant productivity in one of the two study areas and a positive trend in the other. Moreover, plant productivity increase, following fertilization, appeared to have a detrimental effect on the soil pH-plant productivity relationship. Findings support the original hypotheses and strengthen the idea that plant diversity-mediated soil pH-plant productivity relationships are a result of the more intense plant speciation that occurred under the more ＂typical＂ soil conditions of higher pH in temperate as opposed to tropical regions