为解决气井积液预警不及时、排采介入滞后、劳动强度大、制度优化难等问题,通过分析收集21井次的井底测压数据,建立了中江气田气井积液程度3级分类标准,形成了多指标的井筒积液数字综合识别方法,对158口井进行诊断,正确率达92.4%。结合...为解决气井积液预警不及时、排采介入滞后、劳动强度大、制度优化难等问题,通过分析收集21井次的井底测压数据,建立了中江气田气井积液程度3级分类标准,形成了多指标的井筒积液数字综合识别方法,对158口井进行诊断,正确率达92.4%。结合各排采工艺应用界限和经济分析,创建了智能决策系统,并借助计算机编程、工业自动化控制、物联网互联等将智能决策系统与智能排液采气技术一体化,在JS 203-7 HF、JS 104-3 HF井成功应用,实现了井口压力数据自动收集、气井积液程度自动识别、排液采气措施自动判断、排液采气参数自动调整。JS 203-7 HF井及时介入智能泡排后产能递减率由76.00 m 3/d降低到6.37 m 3/d,JS 104-3 HF井及时介入智能柱塞后实现稳定排液且日增产天然气3000 m 3/d。智能决策系统和智能排液采气装置,能有效降低气井产量递减速度,提高最终气藏采收率,对致密砂岩气藏、页岩气藏的智能化排采技术具有借鉴意义。展开更多
The process of decision making and risk analysis are essential tasks along the construction project cycle. Over the years, construction practitioners and researchers have used various methods, tools and techniques to ...The process of decision making and risk analysis are essential tasks along the construction project cycle. Over the years, construction practitioners and researchers have used various methods, tools and techniques to evaluate risk and assist in making more concise decisions. Most practitioners, however, rely on their expert judgment, past experience, intuition, acquired and accumulated knowledge and gut feelings to make decisions. Aleatory （natural, heterogeneity and stochasticity） and epistemic （subjective, ignorance） are the two major types of uncertainties observed in natural sciences. Practitioners traditionally deal with aleatory uncertainty through probabilistic analysis based on historical data （frequentist approach）; and epistemic uncertainty, on the other hand, handled through the Bayesian approach which has limitations since it requires a priori assumption. This paper reports the application of the DST （Dempster Shafer Theory） of evidence to determine the most critical risk factors affecting project cost contingencies using their epistemic probabilities of occurrence. The paper further discuses how these factors can be managed to enhance successful delivery of infrastructural projects. It uses the mixed methodology, with data gathered through structured questionnaires distributed to construction clients, contractors, professionals and experts in the built environment. The research revealed that design risk, financial risk and economic risk were most important cost risk categorizations. In particular, scope changes, incomplete scope definition, incomplete design, changes in specification, micro and macroeconomic indicators and delayed payment problems were identified as the most important risk factors to be considered during the cost contingency estimation process, hence successful delivery of infrastructural projects. The paper concludes by recommending modalities for managing the contingency evolution process of risk estimation to enhance successful delivery and management of infrastructural projects.展开更多
文摘为解决气井积液预警不及时、排采介入滞后、劳动强度大、制度优化难等问题,通过分析收集21井次的井底测压数据,建立了中江气田气井积液程度3级分类标准,形成了多指标的井筒积液数字综合识别方法,对158口井进行诊断,正确率达92.4%。结合各排采工艺应用界限和经济分析,创建了智能决策系统,并借助计算机编程、工业自动化控制、物联网互联等将智能决策系统与智能排液采气技术一体化,在JS 203-7 HF、JS 104-3 HF井成功应用,实现了井口压力数据自动收集、气井积液程度自动识别、排液采气措施自动判断、排液采气参数自动调整。JS 203-7 HF井及时介入智能泡排后产能递减率由76.00 m 3/d降低到6.37 m 3/d,JS 104-3 HF井及时介入智能柱塞后实现稳定排液且日增产天然气3000 m 3/d。智能决策系统和智能排液采气装置,能有效降低气井产量递减速度,提高最终气藏采收率,对致密砂岩气藏、页岩气藏的智能化排采技术具有借鉴意义。
文摘The process of decision making and risk analysis are essential tasks along the construction project cycle. Over the years, construction practitioners and researchers have used various methods, tools and techniques to evaluate risk and assist in making more concise decisions. Most practitioners, however, rely on their expert judgment, past experience, intuition, acquired and accumulated knowledge and gut feelings to make decisions. Aleatory （natural, heterogeneity and stochasticity） and epistemic （subjective, ignorance） are the two major types of uncertainties observed in natural sciences. Practitioners traditionally deal with aleatory uncertainty through probabilistic analysis based on historical data （frequentist approach）; and epistemic uncertainty, on the other hand, handled through the Bayesian approach which has limitations since it requires a priori assumption. This paper reports the application of the DST （Dempster Shafer Theory） of evidence to determine the most critical risk factors affecting project cost contingencies using their epistemic probabilities of occurrence. The paper further discuses how these factors can be managed to enhance successful delivery of infrastructural projects. It uses the mixed methodology, with data gathered through structured questionnaires distributed to construction clients, contractors, professionals and experts in the built environment. The research revealed that design risk, financial risk and economic risk were most important cost risk categorizations. In particular, scope changes, incomplete scope definition, incomplete design, changes in specification, micro and macroeconomic indicators and delayed payment problems were identified as the most important risk factors to be considered during the cost contingency estimation process, hence successful delivery of infrastructural projects. The paper concludes by recommending modalities for managing the contingency evolution process of risk estimation to enhance successful delivery and management of infrastructural projects.
