Production performance and decline laws of gas wells in low-permeability gas reservoirs are affected by multiple fac-tors, so distinguishing the influential laws of each factor is significant to predict the production performance of gas wells and guide the efficient development of gas fields. The factors influencing pressure and production decline laws of low-permeability wells are divided into two types (i.e., static reservoir factors and dynamic production factors) based on the development concept of constant-production pressure dropping in the early stage of gas reservoir production and constant-pressure production decreasing in the late stage. Then, the influential laws were comprehensively analyzed by means of numerical simulation. It is indicated that pressure decline law of gas wells in the early stage of production is mainly affected by gas well controlled reserves, production proration and water production and that in the late stage is mainly dominated by seepage capacity, multi-well interference and water production. Static reservoir factors are prereq-uisite to the development potential of gas reservoirs, and dynamic production factors can be optimized or adjusted by means of rational methods so that gas wells will be in the best production state. In the actual production, static and dynamic factors shall be combined. It is necessary to describe the dynamic production factors in detail according to the gas field development target so as to provide the guidance for production system adjustment and verify the accuracy of gas reservoir understanding.

LWD curves can not fully represent the actual characteristics of shale formations due to environmental factors,and so to improve the accuracy of geosteering and to improve the rate of drilling in high-quality shale formations,real-time calibration is needed.Taking horizontal wells with LWD data in Weiyuan Shale Gas Industry Demonstration Zone as research objects,the characteristics of LWD curves under different environment were evaluated quantitatively and qualitatively to construct calibration charts.Optimal fitting,numerical iterative and other techniques were deployed to establish calibration models for relevant charts.Feasibilities of such operations were analyzed by using core data from laboratories.In this way,one complete package of calibration techniques for impacts of environmental factors on LWD curves of shale formationa was obtained.The newly-developed techniques were used in the LWD data processing from shale formation of 12 horizontal wells in the Weiyuan Area.Relevant results showed that such calibration can effectively eliminate the negative impacts of stratigraphic electrical anisotropy,relative angle,borehole environment,instrument deviation,drilling fluid density and other environmental factors to obtain the features of penetrated formations more accurately.

利用研究区丰富的岩心、测井及地震资料,分析了玉门油田老君庙构造带古近系白杨河组M及L-M层的沉积特征,确定了沉积相类型,明确了其沉积相分布样式,并在此基础上探讨细粒冲积扇的主控因素.研究表明:研究区目的层发育以砂岩沉积为主的细粒冲积扇沉积,M层自下而上发育扇根和扇中亚相,L-M层发育扇缘亚相,粒径向上变细,整体为一退积型冲积扇.冲积扇在平面上呈伸长扇形,宽度为5 ～10 km,长为10 ～ 15 km,厚度为15 ～25 m,冲积扇的根部发育下切河道,宽度为2 ～4 km,受地势的影响,顺物源砂体呈厚度薄、分布范围广的分布特征.细粒冲积扇的形成及沉积特征是气候、物源和古地形等因素共同控制的结果,山间河道出山口后开阔的地势为冲积扇提供了有利的地形,白垩系泥岩和砂岩作为母岩以及山间河道出山口前平缓的地势影响了细粒冲积扇的粒度,同时干热环境加剧了母岩的风化程度,三种因素综合导致研究区形成了细粒冲积扇.

页岩储层特征对于页岩气的赋存状态、含气量和后期开发均具有重要意义.湖相页岩多处于生油窗阶段,其储层特征与海相页岩区别较大.以柴达木盆地北缘中侏罗统页岩为研究对象,利用岩芯观察、有机地球化学分析、XRD矿物成分分析、低温氮气吸附、FE-SEM以及甲烷等温吸附等手段分析页岩储层的岩石类型、地化、矿物组成、孔隙结构和含气性特征.结果表明,与海相页岩相比,柴达木盆地北缘中侏罗统页岩具有“两高两低两种类型”的特点,即有机碳含量高、黏土矿物含量高,热演化程度低、脆性矿物含量低,有机质类型以Ⅱ、Ⅲ型为主.较低的热演化程度导致样品有机质孔隙发育较少;有机酸的溶蚀作用及矿物的转化作用是次生孔隙形成的主要因素.与海相页岩不同的是,高丰度低演化程度导致该演化阶段以产液态烃为主,且样品中可溶有机质含量较高,它对于样品的孔隙结构和甲烷赋存状态都有影响,表现为随比表面积增大,样品等温吸附实验结果呈现下降的趋势.对于高丰度低演化程度湖相页岩储层特征的研究,不仅为柴达木盆地北缘中侏罗统页岩气的勘探开发提供地质依据,同时也完善了页岩气地质理论.

Alluvial fan,which develops in the margin of the basin,is a significant sedimentary faci-es type.In recent two decades,great progress has been made in the controlling of distribution,internal architecture and reservoir characteristics of alluvial fans.Firstly,the controlling of fault activities,litholo-gy of provenance,and the base-level cycles on alluvial fan depositional architecture were elaborated.Sec-ondly,three depositional architecture models of alluvial fans and terminal fans were established,inclu-ding the alluvial fan dominated by debris flow,alluvial fan co-dominated by debris flow and fluvial and fluvial fan.Thirdly,how depositional fabric and mechanism of alluvial fan control the reservoir quality was analyzed.Further research is required on the process of deposition,internal architecture and reservoir het-erogeneity of alluvial fans through advanced technologies,such as advanced flume simulation experiment, numerical simulation of deposition,GPR and so on.

Fumaric acid production by fungal fermentation from renewable resources has received much attention, but suffers from low productivity and yield largely because of poor cell morphology limiting mass transfer. In this study, a simple seed culture medium was developed with soybean meal hydrolysate (SMH) as the nitrogen source for controlling the morphology of Rhizopus oryzae ATCC 20344. With the optimal seed culture conditions (pH 3.0, SMH concentration: 30% (v/v), and inoculation spore concentration: 8 x 10(7)/L uniformly dispersed mycelial clumps with a diameter of similar to 0.1 mm were formed, which gave high fumaric acid production from glucose in shake flasks, reaching a fumaric acid titer of 50.2 g/L and yield of 0.72 g/g glucose. Compared to the fermentation with cell pellets, the fermentation with mycelial clumps generated with SMH as nitrogen source increased fumaric acid production because of improved mass transfer. This process can lower the cost for bio-based fumaric acid and provide a novel way of using soybean meal besides its current use as animal feed supplement. (C) 2014 Elsevier Ltd. All rights reserved.

应用铸体薄片、扫描电镜等岩心分析化验资料，对老君庙油田M油组成岩作用强度进行定量表征，并判断成岩阶段和成岩序列，在此基础上划分出4种成岩储集相，总结了成岩储集相的平面分布样式。结果表明：研究区压实作用以中等压实为主，溶解作用强度弱，胶结作用强度以中—强为主，且以碳酸盐胶结作用为主，碳酸盐胶结作用对本区储层质量起着关键的控制作用；成岩储集相类型包括低杂基、中压实、弱碳酸盐胶结相相对优质储集相（A相），低杂基、弱中压实、中碳酸盐胶结相较有利低渗储集相（B相），低杂基、弱压实、强碳酸盐胶结特低渗-致密储集相（C相），高杂基、中压实、弱碳酸盐胶结低渗-致密储集相（D相）。其中，A相储集性能最好，B相次之，C相和D相最差。

通过薄片、扫描电镜、阴极发光、岩心物性及测井曲线对老君庙油田古近系M层进行了储层特征与形成机理研究,包括沉积储层基本特征、成岩作用及孔隙演化分析等.结果表明,M层为快速堆积下的沉积物,分选差,杂基含量高,总体属于相对细粒的冲积扇相沉积;主要储集空间为粒间孔,为中孔低渗储层;成岩作用类型主要有压实、胶结和溶解作用等.沉积作用控制了储层的原始孔隙度,杂基含量高,分选较差的储层原始物性差,主要分布在扇根片流带片流砂坝和扇中漫流带;相比而言,低杂基含量,分选相对较好的辫流带砂岩受到碳酸盐胶结物的影响大,胶结作用进一步降低了这类储层物性,使储层整体物性表现为低渗透.杂基含量和碳酸盐胶结是导致储层为低渗透的主要因素.

应用老君庙油田较丰富的钻井资料和多年积累的地质研究成果,从沉积过程角度出发,对其河口坝较发育的L11小层进行了储层构型研究,并对基于沉积过程的河口坝储层构型分级系统进行了探讨.该系统以末端水下分流河道控制形成的单一成因河口坝为三级构型单元(同时也是基本的研究单元),以主干水下分流河道控制形成的单一成因河口坝复合体为四级构型单元,以多个主干水下分流河道控制形成的河口坝复合体为五级构型单元.确定了单一成因河口坝的识别标志,在研究区共识别出14个单一成因河口坝.在此基础上,通过横切物源剖面及顺物源剖面确定各单一成因河口坝沉积的先后顺序,结合三维综合分析,最终阐明了各单一成因河口坝的时间演化序列.在沉积学原理的指导下,恢复了研究区复合河口坝的形成过程,明确了河口坝的规模及河口坝间的叠置样式与其形成过程间的耦合关系.

Sequence-stratigraphic and sedimentologic theories and methods were employed in the study of sequence strati-graphic features and sedimentary system distributions in the Baiyanghe Formaiton of the Laojunmiao structural belt in Yu-men oilfield,Jiuxi Basin,northwestern China.Data gathered through core and outsrrop observation and analyses,drilling and logging,and sesimic events,were resorted to establish sequence stratigraphic framework,determine the types and dis-tribution of sedimenatry facies,and understand evolution pattern and controlling factors in the Formation.The result shows that the Formation can be described as a complete three-order sequence, which can be divided into 7 quasi-sequence sets.Sedimentary facies including alluvial fans,braided rivers,braided river deltas and lake depostis,were recognized in the sequence.Depositional facies varied vertically from alluvial fans to braided river delta and then to lake flooding mud-stone and finally to delta.Horizontally,the facies presents itself as a near southeast-northwest sedimenatry system-a sedi-mentary sequence of water transgression and regression.Paleogeomorphology controlled the distribution of the sediments of lowstand system tract of the three-order sequence and climate affected the types of sediments and controlled the superim-posed style and evolution pattern of the sediment in the Formation.

To identify the factors and mechanisms affecting reservoir micro-heterogeneity in the same type of microfacies at different stages of cycle, the main controlling factors of the reservoir micro-heterogeneity of the mouth bar in Es2-9 Formation of the Shengtuo Oilfield were analyzed based on the sedimentary dynamic analysis of high resolution stratigraphic sequence and quantitative parameters of reservoir micro-heterogeneity. The base level cycles of different stages have a differential control on the reservoir micro-heterogeneity of the mouth bar. The changes of the base level in different orders lead to variation in accommodation space and sediment supply, and in turn changes in sedimentary environments of mouth bar at different stages, as a result, the reservoir micro-heterogeneity of the single mouth bar in short-term base level cycle is strong at bottom and weak at top, the reservoir micro-heterogeneity of compound mouth bar (formed by different stages of single mouth bar) in middle-term base level cycle gets weaker from bottom-up, and the reservoir micro-heterogeneity of compound mouth bar at different stages of long-term base level cycle has no obvious pattern.

为揭示基准面旋回对不同旋回阶段河流相储层物性差异及声波时差测井响应的影响,运用基准面旋回沉积动力学原理,对岩心分析化验数据等实测资料进行分析,对孤岛油田中一区馆陶组上段3砂层组河流相储层物性差异主控因素进行分析,明确了基准面旋回对河道微相在不同旋回阶段储层物性差异和声波测井响应的控制机理,并确定了不同级次基准面旋回内河道储层物性分布特征和声波测井响应差异.结果表明:不同级次基准面升降引起可容纳空间与物源供给条件的改变,导致不同旋回阶段河道储层沉积环境出现差异,使短期基准面旋回内部单河道内部储层物性正韵律分布、声波测井响应差异不大;中期基准面旋回中组成复合河道的多期单河道间储层物性自下向上呈总体变好趋势、声波测井响应有异;长期基准面旋回中多期复合河道间储层物性呈无规则分布、声波测井响应差异明显.

基于已有的河流相砂体发育模式,本文应用相控正演模拟法对大井距条件下秦皇岛32-6油田北区(NmⅡ-4小层)河流相砂体(的叠置关系)进行了精细描述.在此过程中,明确了河流相砂体可识别条件,建立了单河道砂体边界识别标志正演概念模型,总结了单河道砂体边界识别标志正演响应波形特征,最终识别出单河道和单一点砂坝边界.研究结果表明:在该区目的层段地震波主频近60Hz条件下,应用相控正演模拟法能在较大井距间时准确识别出单河道和单一点砂坝边界,提高了大井距条件下河流相砂体构型分析精度.

To identify the influence of base-level cycle on the macro-heterogeneity differences of the reservoir among the same type of microfacies in different stages of base-level cycle,using the dynamic principle of the high resolution stratigraphic sequence sedimentation is to analyze the main controlling factors of the reservoir macro-heterogeneity of the estuary dam in Es_2-8 formation of Shengtuo Oilfield on the basis of statistical data and core test material,and this study illustrates the control mechanism of base-level cycle on the macro-heterogeneity differences of the reservoir among the estuary dam in different stages of base-level cycle.Besides,this paper concludes the distribution characteristics of the reservoir macro-heterogeneity among the estuary dam in different stages of base-level cycle.The results show that the base-level cycle in the different ranks goes up and down,which results in the change of accommodation and sediment supply condition and leads to appearance of difference in reservoir sedimentary environment of estuary dam in the different stages.It makes that the reservoir macro-heterogeneity of the upper part of the single estuary dam in short-term base-level cycle is lower than that of the basal part,and the reservoir macro-heterogeneity of the upper part of the compound estuary dam(formed by different stages of single mouth bar)in middle-term base-level cycle is lower than that of the basal part.What's more,the reservoir macro-heterogeneity of the compound estuary dam in the different stages of long-term base-level cycle is distributed irregularly.