ABSTRACTS AND AUTHORS

S AND AUTHORS

The Status，Problems and Countermeasures of LNG Industry Development in China

By LU Zhengguang，GAO Zhenyu，PI Lishi，CHEN Hongyu，ZHOU Ying

ABSTRACT:Through over ten years’development，LNG industry in China has formed a relatively complete industry chain and stepped into a period of quick development.After describing and summarizing current development situation of LNG industry in China，it is thought that in short term，LND industry in China is still confronted with the problems including limited growth rate of market demands，unordered or repeated construction of LNG terminals and liquefying plants and lack of enforceable rules for third party access to LNG terminals and natural gas pipeline network，while in medium and long term，it will be confronted with problems including slow or lagged expansion of downstream market，failure of full reflection of reserve peak-shaving value，not strong power in LNG pricing in international trade and increasingly escalated contradiction and competition with pipeline gas.Therefore，the paper puts forwards suggestions including performing the function of national level strategy to guide the construction of infrastructures of LNG industry and reasonably regulate the market area of LNG and pipeline gas，introducing rules for third party access to LNG terminals and natural gas pipeline network as soon as quickly to promote private enterprises to participate in competition，enhancing downstream market development and governmental policies support to realize diversification of downstream markets and improving the supply and demand and import flexibility of natural gas by various approaches to lower the import price of LNG.

LNG industry in China，current status，LNG terminal，third party access，market diversification

EffectofDiagenesis on Petrophysical Properties of Shahezi Formation，Jinshan Gasfield

By CHEN Jun，DING Xiaoqi，LIANG Xiaolong，HU Yuchuan，JIANG Qi，ZHANG Yongmei

ABSTRACT:In Jinshan gasfield，large-scale tight sandstone reservoirs with low permeability are developed in the Shahezi Formation.In particular，there is better exploration potential in some belts with relatively high porosity and permeability，and industrial gas flow was obtained from many wells.In this study，both reservoir characteristics and diagenesis of the Shahezi Formation were analyzed on the basis of thin-section and casting thin-section identification，SEM，X diffraction of clay，and some petrophysical data.Results show that（1）this reservoir is mainly composed of medium-to coarse-grained lithic arkose and secondly arkoses，and its space includes primary intergranular pore，enlarged intergranular pore，feldspathic intragranular dissolution pore，lithic intragranular dissolution pore，and dissolution fracture；（2）it dominantly experienced compaction and pressure solution，cementation and metasomatism，and dissolution in which，diagenesis affected petrophysical properties evidently，both compaction and cementation brought about a decrease of large amount of primary pores to further make these properties poorer，and dissolution formed plenty of secondary pores

or even dissolution pores，which might advance these properties a lot and control the development of relatively favorable reservoirs.

Key words:reservoir characteristics，diagenesis，Shahezi Formation，Jinshan gasfield

A MethodtoCalculateParametersof Complex and Tight Sandstone Reservoirs

By CHENG Li，FENG Minggang，WANG Kun，LI Sulan

ABSTRACT:There are mainly tight reservoirs with low porosity and permeability developed in Qianfoya Formation.And the type and space of reservoir rock are various and complex.Furthermore，different resistivity appears in well logging because of various reservoir fluids.As a result，it is very difficult to accurately calculate mineral composition of reservoir rock and petrophysical parameters of reservoir.In this study，through core calibration well-logging data，a model to calculate porosity was established at first for different lithology and various types of reservoirs on the basis of rock physics volume model and multiple-parameters mathematical statistical analysis；and then，another model to calculate permeability was developed according to a relationship between porosity and permeability；thirdly，some parameters about formation resistivity or formation water were determined for Qianfoya Formation；at last，a method to calculate saturation suitable for this formation was also set up. These parameters calculated by established models were compared to those obtained from core analysis.Consequently，higher accuracy in well-logging calculation can meet the demand in calculating reservoir parameters.

Key words:complex tight sandstone，reservoir type，calculation of reservoir parameter，Qianfoya Formation

Correlation of TOC and Gas-bearing Property of Shale in Longyin Formation，QY 1 Well

By ZHANG Benjie，LIU Jia，ZHANG Wei，QIN Qin，LUO Sha

ABSTRACT:Some mud shale cores from the Lower Permian Longyin Formation in QY 1 well and some data from geological mud logging were analyzed in terms of a correlation of both organic carbon content and gas-bearing property as well as their influencing factors.Results show that for the shale，its organic carbon content is low whereas its gas-bearing property is high，so representing a weakly negative correlation.In addition，it’s deemed that a sedimentary environment with low salinity is a factor affecting low content of organic carbon，illite/smectite compound mineral is another one influecing organic carbon content，and rich N2is the main one controlling high gas-bearing property.

Key words:Longyin Formation，TOC and gas-bearing property，weak negative correlation，sedimentary environment，illite/smectite compound mineral，rich N2，mud shale

Characteristics of Trap Development and Exploration Prospects，Weihe Basin

By LI Zheng，ZHANG Yang，LI Mengyao，MA Weimin

ABSTRACT:To study trap is a significant component of making petroleum geology clear.Types of oil and gas reservoirs can be classified by means of trap features.Meanwhile，different features can reflect various origins to form these reservoirs.So，trap elements are the important index to evaluate an exploration potential for a lot ofoil and gas basins.In order to further understand the characteristics of oil and gas resources in Weihe Basin，the basin structure，sedimentary history，and many data from drilling and well logging in some geothermal wells were analyzed on the basis of previous achievements.Results show that（1）there are different trap types developed，including structural traps（anticline and fault traps），lithological traps（lithologic updip pinch-out traps and sand lens lithologic traps），stratigraphic traps（only stratigraphic overlapping traps），and compound traps（structural-lithological compound traps and structural-stratigraphic compound traps）；and（2）different trap types are located at different zones or strata.Some deep and highmaturity pyrolysis CH4and He traps are located at steep slope area of southern basin；and the main types are fault traps and their compound traps.In addition，shallow biogas traps are mainly situated at the steep slope area of northern Gushi depression，and the main type is lithological trap.

Key words:Weihe Basin，water-soluble gas，trap，fault，gas reservoir

Prospects of Shale Gas in Lower Carboniferous Jiusi Formation，Weining Area

By TANG Xiangui，LIU Taiqin，XIAO Hong，XU Wenhui，LIU Feng ABSTRACT:Based on previous evaluation on shale-gas resources in southwestern Guizhou province，integrated many achievements from drilled shale-gas investigation wells and shale-gas discovered wells in this area or surrounding areas，we carried out a study on shale gas of the Lower Carboniferous Jiusi Formation in terms of its development，geochemical and reservoir characteristics，and gas-bearing property.In addition，according to basic geological condition，shale-gas geological condition，and some standards to optimize favorable shale-gas belts，we selected two prospects of both Longjie syncline and Weishui anticline，which guide an exploration and development of shale gas in Weining area.

Key Words:Weining area，Jiusi Formation，shale gas，geological condition，favorable shale-gas belt，prospect

Countermeasures Against Improving Flowback Efficiency for Tight Sandstone Gas Reservoirs

By ZHONG Sen，WANG Xingwen，CI Jianfa

ABSTRACT:For most gas wells，flowing back after fracturing is a vital part of stimulation，which may affect directly a fracturing effect.Core experiments show that the main factors influencing flowback velocity are the start-up pressure caused by fracturing-fluid filtration and the flowback differential pressure；and the proppant backflow is influenced by formation closure pressure and the viscosity of gel breaking fluid.Due to strong water sensitivity and severe water-blocking damage existing in many tight sandstone gas reservoirs of western Sichuan Basin，a rapid drainage is needed to reduce this damage.Therefore，an efficient flowback technology of horizontal well is proposed.Firstly，liquid nitrogen energized-assisted drainage is adopted to provide a higher differential pressure of flowback，and a mode of accompanied injection with“stepped”discharge reduction is optimized；secondly，fiber sanding is used to improve the stability of proppant in fractures，and during a staged fractureing，a certain proportion of tail chase should be implemented in the final operation of every stage.This technology has been applied to over 30 wells in middle-shallow layers，resulting in improvement of flowback velocity and final flowback rate. Key words:staged fracturing，rapid drainage，liquid nitrogen energization，fiber sanding，tight gas reservoirs

Prediction of Borehole Collapse Cycle in Shale Reservoirs，WY Structure

By LONG Zhangliang，LI Hui，WEN Zhentao，ZENG Xianwei

ABSTRACT:In mud shale，there are large amounts of water-sensible clay minerals.When in contact with drilling fluid，the mud shale interacts with drilling fluid each other，which may lead to swelling due to hydration.This alters the stress distribution near borehole.And one problem of borehole instability in mud shale becomes more serious than that of stress instability in conventional constant elastic parameters.So，it’s more difficult to predict borehole collapse cycle.Our study deems to establish a quantitative correlation between borehole stability and change of drilling-fluid soaking-time.To make rock mechanical parameters clear is very important in this correlation.So，through some experiments，the first relationship that these parameters changes with soaking time is established；and then，the second one that collapse pressure varies with time is set up；at last，the third one that collapse width changes with soak time may be gained.It’s demonstrated that one cycle should be no obvious change that the width increases.At this time，borehole stress reaches a balance again.This procedure avoids a complicated mechanical and chemical match，and finally can realize an aim to predict the collapse cycle very accurately.

Key words:shale reservoirs，borehole stability，collapse width，collapse cycle

Real-time Transmission System of Downhole Micro-flow Measurement

By LI Guo，WANG Zhen，LI Qunsheng，ZHENG Yi

ABSTRACT:In micro-flow controlled drilling technology，downhole complicated conditions are mainly estimated by real-time monitoring of inlet and outlet flowing variation of drilling fluid，and wellhead back pressure is adjusted through the opening control of throttling devices.However，by downhole micro-flow tool，the function of real-time transmission can be achieved to provide a guarantee for controlling micro-flow rate efficiently and accurately.Thus，a real-time transmission system of downhole micro-flow measurement is designed.With the system，the signal of downhole tester can be transferred to the ground through MWD，providing some parameters about back pressure and flow control.Its main advantage is the fast processing for accidents of downhole overflow and lost circulation.If there is no accident，it just needs to maintain the stability of annular flow rate and annular pressure；but if many accidents related to pressure occur，the mechanism of pressure control will start to adjust downhole flow and pressure through estimating the annular flow variation and the gas content of invading fluids combining with wellhead parameters.

Key words:micro-flow control，real-time transmission，throttling device，MWD，closed-loop control

Shale-gas Horizontal-well Drilling Technology for JY1HF Well

By ZHANG Yusheng，LIU Qing，ZHU Liping，HU Daliang，JIANG Bo

ABSTRACT:JY1HF well is the first shale-gas horizontal well deployed at Jingyan-Qianwei block of Weiyuan structure，southwestern Sichuan Sag，Sichuan Basin.Its target interval is the Cambrian Qiongzhusi Formation and the drilling depth is 4623 m.There arelots of difficulties during drilling this deep marine strata，containing poor drillability，strong abrasiveness，long horizontal length，and low cementing quality under long openhole or by oil-based drilling fluid.So，some technologies were applied to this well，including highly efficient optimization of drilling bit，turbo drilling，PDC bit integrating with oil-resisting motor drilling，oil-based drilling fluid with strong sealing capability，and optimized casing string and slurry system.Better effects were obtained，for example，the drilled horizontal length of 1203.72 m，the average ROP in the marine strata increased by 96%compared to some adjoining wells with same hole size，the average ROP in this shale bed raised 6.1 times faster than those adjoining wells with same hole size，smooth well trajectory，casing running right the first time，and excellent cementing quality. Key words:shale-gas horizontal well，impregnated bit，turbo drilling，oil-based drilling fluild，JY1HF well

Improving Measures for Wen23 TEG Dehydration System

By ZHANG Hongjing，SU Huawei，YANG Xun

ABSTRACT:On the basis of an analysis on some problems existing in Wen23 TEG dehydration devices，some improving measures are put forward，such as:installing flash drum，adopting efficient plate heat exchanger of glycol rich and lean solution，replacing diaphragm glycol cyclic metering pump with energy conversion pump，adjustable outer circulation of regenerating column top，and optimizing technical parameters.Results show that these measures can enhance their adjustability and operability，and reduce the operating cost and energy consumption as well as TEG loss.Thus，they have popularization value for the design and technical innovation of dehydration devices.

Key words:TEG，dehydration device，technical improvement

Simulation and Energy-saving Optimization of DEA Acid-gas Removal Technology

By HAN Ce，ZHANG Wei，ZHANG Weiwen，FU Siqiang，AN Xu

ABSTRACT:Shale gas produced from reservoirs often contains large amount of acid gas which may corrode pipelines and equipments during gathering and transportation.Thus，it should be purified to remove the acid gas.In this study，HYSYS 8.4 is applied to shale Block 1 for simulated calculation of DEA acid-gas removal technical process；the plate number of absorption and generation towers is fixed；and the acid-gas load in DEA solution and the variation rule of total energy consumption are observed through changing the circulation rate of DEA solution and the DEA mass fraction. Results show that reducing the circulation rate and mass fraction can increase the acid-gas load，and significantly lower the total energy consumption.Moreover，by parameter optimization of acid-gas removal technical process，the operation costs have been reduced with a 5.9%increase in acid-gas load and a 10.6%decrease in total energy consumption.

Key words:shale gas，acid-gas removal treatment，HYSYS simulation，circulation rate of DEA solution，DEA mass fraction

Pitting Behavior of 2205 Duplex Stainless Steel in Ethylene Glycol Saline Solution

By ZOU Yongli，JIANG Chengbin，REN Shunshun

ABSTRACT:Integrated some tests of chemical immersion corrosion with a method of surface observation，we studied the effects of Cl and deoxidant concentration on the pitting behavior of 2205 du-

plex stainless steel in O2-saturated ethylene glycol saline solution. Results show that the maximum pitting depth and average weight loss of the steel may increase with the Cl concentration.When the solution temperature and Cl concentration reach 90℃and 48276 mg/L，serious pitting appears at the sample surface with the maximum pitting depth of 0.305 mm.Furthermore，the higher the NaCl concentration is，the larger the maximum pitting depth and average weight loss of the 2205 samples are.

Key words:2205 duplex stainless steel，ethylene glycol，chloride ion，pitting，pitting depth

Application of TGNET Software to Operational Scheduling for Gas Pipelines，Western Sichuan Basin

By LUO Linjie

ABSTRACT:So far，gas pipeline systems with more and more large-sized peak-shaving and gas-boosting facilities become more complex.In this study，TGBET software was applied to operational scheduling for gas pipelines in western Sichuan Basin.At first，a model of gas pipelines was established for this area to implement an analogue simulation；and then，one technology of steady-state simulation was used to optimize an operational scheduling plan of booster set；at the same time，another technology of dynamic-state simulation was used to formulate an emergency scheduling.Results show，if working condition varies with time，the dynamic simulation can provide technological evidence for accurately making decision of emergency scheduling whereas the steady-state simulation makes this scheduling more simple and convenient.

Key words:western Sichuan Basin，gas pipelines，TGNET software，operation scheduling of booster air compressor，emergency scheduling

Fuzzy Evaluation of Market Competitive Advantages of Natural Gas Marketing Enterprise

By XIAO Jun，XIONG Zhijian，YUAN Jianli，ZHANG Daohua，ZHAO Yun

ABSTRACT:With regard to the natural gas market competition in China，the paper has a brief review of studies on market competitive advantages and constructs a competitive advantage evaluation index system of natural gas marketing enterprises for fuzzy and comprehensive evaluation on the market competitive advantages of one natural gas marketing enterprise.In the system，an evaluation factors set composed of 31 factors from 7 categories and 5 evaluation classes are put forward，index weight is determined，an evaluation matrix is established and comprehensive membership degree is calculated to judge the market competitive advantages of enterprise. Evaluation results show that the natural gas marketing enterprise has strong market competitive advantages and its various criteria show strong superiorities.The paper also puts forward some suggestions.

Key words:natural gas marketing enterprise，market competitive advantages，evaluation index system，fuzzy evaluation，index weight

Thinking on Strategies for Rural Gas Market Development in the Context of Building a Well-off Society in an All-around Way

By ZOU Xiaoqin，WANG Wenjing，WU Qing，WANG Lixian

ABSTRACT:Optimization of energy consumption structure is a necessary and effective approach for the construction of a beautiful countryside.To promote the development of gas market in rural area and boost the construction of a well-off society，the paper studies the development tendency and strategies of gas market in rural area during the construction of a well-off society in an all-around way. Based on the research analysis on current energy consumption condition in rural area，it studies and judges the development tendency of gas market in rural area and points it out that the gas market demands and consumption in rural area will maintain continuous steady growth，the proportion of gas in energy consumed in rural area will increase at a large degree and it will become an important part of energy consumed in rural area.Considering current development situation and characteristics of gas market in rural area，the paper advocates positive and stable market development，consumers classification and grading，optimization of gas pipeline network layout，integration of town，urban and rural markets，communication with local government，combination between rural market and urban and industrial markets and emphasis on technology and safety，so as to lay a solid foundation for future development of market.

Key words:construction of a well-off society in an all-around way，rural gas，natural gas，market strategy

Coupling Analysis on Natural Gas Distributed Energy System and In tegrated Oil and Gas Enterprises

By ZHANG Chengdong，WANG Li，ZHENG Zhibin，XU Jianwei，TANG Gang

ABSTRACT:On the basis of deeply acknowledging the significances of development of natural gas distributed energy system，the paper conducts coupling analysis on the unique advantages of integratde oil and gas enterprises and many factors restraining the development of natural gas resource in China.Analysis results show that if Integrated oil and gas enterprises establish distributed energy source system in oil and gas field office area，living quarter and residential area or places near other production enterprises in rigid demand of cold，heat and electricity by means of capital participation，cooperative development and gas supply guarantee and support and participate in the construction of distributed energy system of local government and energy consuming enterprises，the adverse factors restraining the development of natural gas distributed energy system will definitely be weakened and even eliminated and then the development of enterprises and natural gas distributed energy system will be promoted bilaterally and sustainably and the national energy development strategy of energy conservation and emission reduction will be boosted.

Key words:natural gas，distributed energy system，integrated oil and gas enterprises，coupling

Impacts of International Oil Price Fluctuation on Benefits of Shale Gas Development and Utilization

By WANG Kai，HU Zhengxiong，YOU Jing

ABSTRACT:Shale gas development in America has been greatly affected by the drop of oil price.Whether same problem will occur in China and how the international oil price fluctuation will affect the economic benefits brought by shale gas development and utilization become problems urgently to be answered.In this respect， the paper takes the shale gas output，number of drilled wells and single-well investment scale in Jiaoshiba Block of Fuling Shale Gas Field，Chongqing as examples and calculates the economic benefits brought by shale gas development and utilization in China under the fluctuation of international crude oil price.Results show that on the premise that the investment to one single shale gas well is RMB70 million，if the crude oil price fluctuates between USD40～100/bbl，shale gas development will be more beneficial than crude oil import no matter fiscal subsidies are considered or not.But if the crude oil price fluctuates around USD40/bbl，the shale gas sale price will not make shale gas utilization more beneficial than crude oil import.The central government subsidies（RMB0.4/m3）provided to shale gas development will be transferred to shale gas utilization and it will be favorable to improvement of shale gas utilization benefits.

Key words:shale gas，development and utilization，oil price，economic benefits

Research on Optimization of Bid Invitation and Evaluation Indexes of Oil and Gas Field Enterprise and Application

By ZHONG Yi，LI Tao，YANG Dan，LI Congfei，MA Xin，LI Zizi

ABSTRACT:To solve the problems encountered in the preparation of bids in accordance with industrial bid evaluation standards of oil and gas field enterprises，such as the non-uniform weight ratio of technical bid and commercial bid，failure of bid evaluation indexes in fully reflecting the particularities of natural gas industry and failure of bid evaluation standards in covering various items，a bid evaluation index system with echelon structure and complete bid evaluation indexes covering materials purchasing and engineering services specialties of natural gas enterprises should be established to make it have characteristics including universality，feasibility，extensiveness and operability.For this purpose，ideas and schemes for the optimization of bid invitation and evaluation indexes for materials purchasing and engineering services of oil and gas field enterprises are put forward and empirical analysis is carried out for them.

Key words:oil and gas field enterprises，materials purchasing，engineering construction，bid invitation and evaluation indexes，optimization and improvement

Primary Investigation on Funds Management of Soft Science Research Projects from the Perspective of Audit

By PU Rongrong，SUN Wei，XIE Jianjun，DENG Jingwei，XU Jianwei

ABSTRACT:In recent years，special audit on scientific research funds becomes more and more.Aiming at the problems in audit of soft science projects，this paper takes PetroChina Southwest Oil and Gas Field Company as an example and conducts an objective analysis on primary causes of these problems from the aspects of system，process，management and personnel quality，and also puts forwards relevant measures and suggestions，hoping to realize the target of simplifying procedures and releasing scientific research personnel from the fussy frame through continuous research and improvement of system management.

Key words:soft science research projects，funds management，audit