Innovation and practice of petroleum engineering synergetic management for the development of difficult-to-produce reserves

Due to engineering technology and development costs,a considerable amount of proven oil and gas resources in China are difficult to develop,becoming reserves difficult to produce.Based on the successful development of some domestic oil and gas reserves difficult to recover,this article summarizes the"four in one"petroleum engineering synergetic management model to promote the effective development of these reserves.This model draws on the essence of management theories,such as system theory,cybernetics and synergetic theory,and proposes the development idea of value creating and sharing for this type of reserves.By adopting the new management method of mechanism synergy,speciality synergy,process synergy and industrial chain synergy,this model effectively overcomes the decentralization of management responsibility,different management objectives,great risks of engineering and technological innovation,and the large number of uncertain factors in project construction,and can stimulate the vitality and power of active coordination of project participants,to effectively realize the synergetic innovation of engineering technology and synergetic cost reduction of the whole chain,reduction of the balanced oil price of the project,and dispersion of the project investment risk.By adopting this model,a large proportion of difficult-to-produce reserves have been liberated,realizing the effective utilization of the difficult-to-produce oil and gas resources,and making the reserves an important supplement to ensure national energy security.

The Reform of Elastic-plastic Mechanics Teaching for Petroleum Engineering Related Majors

“Elastic-plastic Mechanics”is an important course for undergraduates and postgraduates of general engineering majors.However,the theoretical derivation of equations is complex,and the connection with engineering practice is inadequate.Therefore,teaching becomes difficult and boring for a number of students.Firstly,this paper introduces the importance of Elastic-plastic Mechanics for petroleum engineering related majors.Based on the recent teaching experience,the teaching reform of Elastic-plastic Mechanics course is carried out focusing on teaching method and learning content,and a discussion teaching mode based on students’independent discussion and engineering cases is formed.Remarkable results have been achieved in improving students’learning efficiency and classroom teaching effect.Furthermore,students’comprehensive ability of independent innovation and practice is enhanced.

The Fifth SPE International Meeting on Petroleum Engineering

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Review of deep learning algorithms in molecular simulations and perspective applications on petroleum engineering

In the last few decades,deep learning(DL)has afforded solutions to macroscopic problems in petroleum engineering,but mechanistic problems at the microscale have not benefited from it.Mechanism studies have been the strong demands for the emerging projects,such as the gas storage and hydrate production,and for some problems encountered in the storage process,which are common found as the chemical interaction between injected gas and mineral,and the formation of hydrate.Emerging advances in DL technology enable solving molecular dynamics(MD)with quantum accuracy.The conventional quantum chemical method is computational expensive,whereas the classical MD method cannot guarantee high accuracy because of its empirical force field parameters.With the help of the DL force field,precision at the quantum chemistry level can be achieved in MD.Moreover,the DL force field promotes the computational speed compared with first-principles calculations.In this review,the basic knowledge of the molecular force field and deep neural network(DNN)is first introduced.Then,three representative opensource packages relevant to the DL force field are introduced.As the most common components in the development of oil and gas reservoirs,water and methane are studied from the aspects of computational efficiency and chemical reaction respectively,providing the foundation of oil and gas researches.However,in the oil and gas problems,the complex molecular topo structures and various element types set a high challenge for the DL techniques in MD.Regarding the computational efficiency,it needs improvement via GPU and parallel accelerations to compete with classical MD.Even with such difficulties,the booming of this technique in the area of petroleum engineering can be predictable.

Geological conditions and reservoir characteristics of various shales in major shalehosted regions of China

China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major controlling factors.This study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale gas.In general,shales in China’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas generation.Marine strata generally show high degrees of thermal evolution.In contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these shales.The shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of shales.These shales are followed by those in the Niutitang and Longtan formations.In contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low porosities.Furthermore,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral contents.Despite a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some extent.For marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production.

An Alternative to Flare Gas Processing:A Feasibility Study of Natural Gas to Liquid Processes

The quantities of gas released into the environment during the extraction and processing of crude oil,by flaring,constitute a vast source of mineral wealth which can be used to produce other useful products.The processes studied in this paper,as alternatives to the above problem,are the ones used in Shell Pearl Qatar project and Oryx GTL project.Both projects produce liquid fuels,mainly naphtha and diesel,in addition to more special fuel such as kerosene.This paper is a feasibility study of a project that makes use of the flare gas from the State of Texas,U.S.A.,as a feedstock to a process similar to either Shell Pearl Qatar project,or Oryx GTL project.The objective of this study is to determine the price range for crude oil over which an investment to similar projects can be profitable.An MS Excel Model was developed in order to perform calculations having as a variable the crude oil price and taking into account all the process and project’s financial data.The results of this model showed that a project similar to Shell Pearl Qatar remains profitable in crude oil price above$57.76/barrel,while a project similar to Oryx GTL remains viable for crude oil price over$31.4/bbl.In the price range$55-$60/barrel,the payout of the corresponding to Shell Pearl Qatar project will be in about 15.2 years and 3.3 years for a project similar to Oryx GTL.Finally,using the financial principles of this study we can apply them to any process in order to determine under what conditions will remain viable.

Methods in Oil Recovery Processes and Reservoir Simulation

The exploitation of an oil field is a complex and multidisciplinary task, which demands a lot of prior knowledge, time, and money. A good reservoir characterization is deemed essential in the accomplishment of Enhanced Oil Recovery (EOR) processes in order to estimate accurately the properties of the porous medium affecting the flow properties. Several techniques at a field scale are currently being used to determine these properties, which are time and money consuming. But these alone do not guarantee the success of the project. Reservoir simulation and numerical techniques were then included in the pre-development and follow-up studies as an effective tool to determine the productivity and future behavior of the oil field. As the computational power increased, more advanced and detailed models were developed, including different chemical and physical phenomena. But alongside this process, there was an active research in the area of reservoir simulation, improving the accuracy and efficiency of the numerical schemes used for the flow, transport, and energy equations. The aim of this review is to address the topics described. Firstly, the origin of an oil recovery process, the economic factors and field tests involved are introduced. Secondly, the oil and porous medium origin and characterization as well as an introduction to the fundamental concepts and equations are associated to reservoir simulation. Finally, a brief description and analysis of the techniques are used in reservoir simulation employing finite difference methods, their downsides and possible ways to overcome these problems.

Persistent Integration and Innovation Management Mode and Its Applications in Petroleum Production Engineering

This paper proposes a new management mode named the persistent integration and innovation management mode to satisfy the requirements by the fast development at oilfields. Taking engineering philosophy as the guidance and technical innovations in petroleum production engineering as the breaking point, the management mode combines long term production practice at oilfields with modern management methods. The management mode integrates intellectuals, techniques, capital, and information and so on to accomplish global optimization of resource configuration. Sets of new techniques, new methods, new technologies and new equipment in petroleum production engineering have been proposed under the guidance of the management mode, achieving great social and economic benefits.

Practice and understanding of developing new technologies and equipment for green and low-carbon production of oilfields

The core of China’s low-carbon development includes optimization of industrial structure,clean energy technologies,emission reduction technologies,and innovation of relevant systems and institutions.China National Petroleum Corporation(CNPC)has always been a proactive participant in developing low-carbon economy,shouldering the responsibilities of safeguarding oil and gas supply,conserving energy,and reducing emission.Therefore,CNPC fulfills those responsibilities as a substantial part of its overall strategy.Guided by low carbon and driven by innovation,petroleum corporations have taken constant innovation of low-carbon technologies,especially the development of green and low-carbon petroleum engineering technologies and equipment,as major measures for energy conservation and emission reduction.Large-scale development mode o f unconventional resource anhydrous fracturing should be innovated.And supercritical C 02 should be used to replace water for fracturing operation,in order to achieve multiple objectives of C 02 burying,conserve water resource,improve single well production and ultimate recovery,realizing reduced emission and efficient utilization o f C 02 resources.Artificial lifting energy-saving and efficiencyincreasing technologies and injection-production technology in the same well should also be innovated.Energy consumption of high water-cut wells is reduced to support the new low-carbon operation mode of high water-cut oilfields and realize energy saving and efficiency improvement during oil production by developing the operation efficiency of the lifting system and reducing the ineffective lifting of formation water.These technologies have been widely recognized by local and international experts and have greatly enhanced CNPC's international influence.This study expounds the key technologies and equipment with regard to the development of green and low-carbon petroleum engineering and provide relevant suggestions.

A review of the shale wellbore stability mechanism based on mechanicalechemical coupling theories

Wellbore instability in hard brittle shale is a critical topic related to the effective exploitation of shale gas resources.This review first introduces the physicalechemical coupling theories applied in shale wellbore stability research,including total water absorption method,equivalent pore pressure method,elasticity incremental method of total water potential and non-equilibrium thermodynamic method.Second,the influences of water activity,membrane efficiency,clay content and drilling fluid on shale wellbore instability are summarized.Results demonstrate that shale and drilling fluid interactions can be the critical factors affecting shale wellbore stability.The effects of thermodynamics and electrochemistry may also be considered in the future,especially the microscopic reaction of shale and drilling fluid interactions.An example of this reaction is the chemical reaction between shale components and drilling fluid.

ANALYTICAL AND APPROXIMATE SOLUTION FOR SPHERICAL SYMMETRY DISPERSIVE TRANSPORT IN POROUS MEDIA

Spherical symmetry convective-dispersive transport of a tracer contamination from continue and slug injection well in semi-infinite porous media has been studied. The analytical solution has been obtained by analytical inversion. The early time approximate solution was given. These solutions were compared and the characteristics of concentration distribution and change were investigated. The results show that in early time and late time the approximate solution is of significance.

NUMERICAL SIMULATION OF PARTICLE SEPARATION IN AN OIL-SAND SEPARATOR

The gathering systems of crude oil are greatly endangered by the fine sand and soil in oil. Up to now, how to separate sand from the viscid oil is still a technical problem for oil production at home or abroad. Recently, Institute of Mechanics in Chinese Academy of Sciences has developed a new type of oil-sand separator, which has been applied successfully in oil field in situ. In this paper, the numerical method of vortex-stream function is used to predict the liquid-solid separating course and the efficiency for this oil-sand separator. Results show that the viscosity and particle diameter have much influence on the particle motion. The calculating separating efficiency is compared with that of experiment and indicates that this method can be used to model the complex two-phase flow in the separator.