Detrital Zircon U-Pb Ages of the Zhaojiazhuang Formation, Middle–South Section, Taihang Mountains, China and their Geological Significance

The sedimentary Zhaojiazhuang Formation overlies the ancient Paleo-proterozoic crystalline basement in the middle-south sections of the Taihang Mountains,China.It is a complete stratigraphic sequence with clear boundaries.The formation has an angular unconformity with the underlying Paleo-proterozoic Tongyu Formation and a parallel unconformity with the overlying Changzhougou Formation from the Changcheng System,which is widely distributed throughout the W utai-Zhongtiao-T aihang Mountains.Qiu Zhen et al.(2007)and Wang Qingchun et al.

Strategic Trends of International Oil Companies

This paper reviews the changes in international oil prices, world oil demand and oil production in 2021-2022, collates the upstream business performance, asset changes, exploration expenditure and progress in reserve replacement of international oil companies, and summarizes the oil production trend, development strategies for oil and gas businesses, energy transition and business diversification of major oil companies in the coming years. The study finds that the oil market has been highly uncertain in recent years, and oil prices may remain at a moderate or high level in the short term;despite the rising oil prices, oil companies are spinning off their upstream businesses;and the differentiated transformation of oil companies has entered a substantive stage. On these grounds, two recommendations for the high-quality development of the oil and gas businesses of Chinese oil companies are proposed: First, Cost decreasing and benefit increasing around the main oil and gas businesses should be continuously promoted;Second, Business planning should be enhanced to achieve global optimal oil and gas businesses.

Practice of Unconventional Gas Development and Engineering Management Innovation in China

This article analyses the recent progressive increase in resource quantity and production quantity of unconventional natural gas in China, describes its natural properties and the concepts, strategies and approaches of its development, summarizes the special techniques, management concepts and development modes formed in the process of its development, and puts forward proposals to accelerate the development of unconventional natural gas of China. The technically recoverable reserve of unconventional natural gas is 1.7 times that of conventional natural gas and its output in 2012 accounted for 41.8% of the total output in China. Chinese tight gas development has gained success, coal-bed methane development and shale gas production pilots have made important progresses. As the key feature of unconventional natural gas is 'low grade', for the effective scale development, developers must build up the engineering concept of low-grade resources development, adhere to the low cost strategy, take the development route of 'a step backward and then a step forward', apply such ideas and methods of engineering management as low cost dualistic integrative innovation, full control network management, economic limit theory, integrated operation and 'four orientations' engineering management, establish a 'two lows' engineering management system, and take reference of the successful development mode of the tight gas in Sulige and the coal-bed methane in the Qinshui basin. In order to achieve the objective of rapid development of nonconventional natural gas in China and to accelerate the development pace, the government should continue toincrease support, to speed up the reform of natural gas price adjustment, to set up national comprehensive development and utilization demonstration areas, to input in sustainable technological research and to promote engineering management innovation.

A review of in situ upgrading technology for heavy crude oil

With the growing demand of oil worldwide,heavy oil has increasingly become vital in the world energy market.However,further development of heavy oil reservoirs are limited by regular enhanced oil recovery(EOR)methods.In situ upgrading technology provides potential for the development of heavy oil and bitumen reservoirs.This study reviews three categories of in situ upgrading methods:solvent-based,in situ combustion(ISC),and catalytic.Solvent-based methods,including cyclic solvent injection,vapor extraction,and hybrid processes,have recently received attention and have been progressed in both laboratory and field applications.However,high solvent costs in relation to the low price of heavy oil have continued to limit the field applications of these techniques.ISC,which may have the potential to develop particularly harsh reservoirs with extremely viscous crude oil,involves complex reaction mechanisms and consists of three main steps:oxidation,combustion,and gas flooding.Yet,complex operating conditions and a low success rate have restricted its application.Catalytic methods,which have demonstrated the potential to refine and upgrade crude oil in a more economic and environmentally friendly way,are often accompanied by conventional thermal EOR methods,such as steam flooding and ISC,and involve a series of hydroprocessing or hydrotreating reactions,such as hydrocracking,hydrodesulfurization,hydrodenitrogenation,hydrodeoxygenation,and hydrodemetallization.However,the high cost and complexity of the reaction mechanisms have limited their applications.

Production analysis in shale gas reservoirs based on fracturing-enhanced permeability areas

Hydraulic fracturing has been widely applied in shale gas exploitation because it improves the permeability of the rock matrix.Fracturing stimulation parameters such as the pumping rate, the fracturing sequence, and the fracture spacing significantly influence the distribution of the stimulated reservoir volume(SRV). In this research, we built a numerical model that incorporates the hydraulic fracturing process and predicts gas production. The simulation of fracture propagation is based on the extended finite element method(XFEM), which helps to calculate aspects of the fractures and the SRV; we imported the results into a production analysis model as the initial conditions for production prediction. Using the model, we investigated the effects of some key parameters such as rock cohesion, fracture spacing, pumping rate, and fracturing sequence on the shale gas production.Our results proved that the SRV was distributed in the vicinity of the main fractures, and the SRVs were connected between the fractures in a small fracture spacing. We obtained optimal spacing by analyzing the production increment. High pumping-rate treatment greatly changes the in-situ stress around the hydraulic fractures and enlarges the field of SRV. Simultaneous fracturing treatment improves the flow conductivity of formation more than sequential fracturing. This study provides insights into the hydraulic fracturing design for economical production.