Occurrence and distribution of dibenzofurans and benzo[b]naphthofurans in the crude oils from the Northern and offshore Niger Delta basin,Nigeria

The occurrence and distributions of dibenzofurans (DBFs) and benzo[b]naphthofurans were investigated in crude oils from Niger Delta, Nigeria, by gas chromatography-mass spectrometry-mass spectrometry. The distribution of DBFs was characterized by the predominance of C₂-dibenzofurans. 4-Methyldibenzofuran was the most abundant among the methyldibenzofurans isomers while dimethyldibenzofuran-2 (DMDBF-2), ethyldibenzofuran-1, DMDBF-3, and DMDBF-6 occurred in higher amounts when compared with other DMDBFs. Among the benzonaphthofurans, the abundance of benzo[b]naphtho[2,1-d]furan was higher than other isomers. The DBFs distributions in the oils were not affected by source facies and depositional environments. However, the DBFs concentrations increased with increasing maturity in oils from ADL and MJO oilfields.     

结合雨水利用的小区景观生态设计初探--以长江三角洲地区为例

以住宅小区景观生态设计基本原则为前提，结合长江三角洲地区的气候特征，探讨适宜于该地区的雨水利用与住宅小区景观生态设计相结合的可行性。并以此为依据对现有住宅小区进行改进的探讨。     

渭北油田密井网水下分流河道储层构型研究及应用

渭北油田是鄂尔多斯盆地南部最近两年新发现的含油区块,本文以其密井网区延长组四段33油组为例,应用岩心、测井、地震及动态等资料,对辫状河三角洲水下分流河道砂体内部构型开展了系统研究。在分析单河道基本发育特征的基础上,剖面上井震结合识别单河道,平面上采用最大单层厚度与砂体层数交绘的方法,在密井网区长33油组识别出八个单河道发育期,单河道宽度一般在500~800m之间,宽厚比介于100~130之间;在平面复合河道中识别出单河道发育条数及分布范围;同时提出长33油组河道内部发育下切叠加式、不完全下切式、孤立式及薄层叠加式四种砂体叠置方式,明确了不同叠置模式在密井网区分布范围,为渭北油田密井网区注水开发和外围有利区带选取提供了地质依据。     

南苏丹Melut裂谷盆地扇体的发现及油气意义

Melut盆地为中非剪切带走滑背景下形成的裂谷盆地,具有早期白垩世被动裂谷盆地和晚期古近纪—新近纪主动裂谷盆地相叠合的特征,长期以来一直围绕辫状河、三角洲等领域进行勘探。通过地质—地球物理综合研究,在盆地北部凹陷识别出一系列扇体沉积,包括凹陷东部Abyat扇三角洲、西部Ruman近岸水下扇等。这些扇体主要形成于盆地初始被动裂谷期,发育于下白垩统Al Renk组烃源岩及烃源岩附近的白垩系Galhak组和Al Gayger组内,具有良好的生、储、盖配置条件。扇体的发现证实了Melut等中非裂谷盆地的初始被动裂谷期同样发育类似于主动裂谷盆地的扇三角洲、水下扇等各种扇体沉积,且具有良好的成藏条件和勘探潜力,这一发现和认识拓展了中非裂谷盆地的勘探潜力和空间。     

A low-distortion multi-bit sigma–delta ADC with mismatch-shaping DACs for WLAN applications

A low-distortion feed-forward MASH2_4b-2_4b sigma–delta analog-to-digital converter (ADC) for wireless local area network (WLAN) applications was presented. The converter exhibits improved performances than the ADCs which have been presented to date by adding a feedback factor in the second stage and employing a 2nd-order noise-shaping dynamic element matching (DEM) scheme. The feedback factor induces a zero in the noise transfer function (NTF) and therefore improves the in-band signal to noise and distortion ratio (SNDR) of the modulator. The mismatch-shaping DEM was introduced and applied to the 4-bit DACs in this paper to improve the resolution and linearity of the ADC. Fabricated in a 0.18 μm CMOS process with single 1.8 V supply voltage, the converter achieves a peak SNDR of 85.4 dB over a 10 MHz bandwidth which implies an effective number of bits (ENOB) of 13.90-bit. The spurious free dynamic range (SFDR) is –94 dB for a 1.25 MHz@–6dBFS input signal at 160 MHz sampling frequency. The occupied area is 0.44 mm² and dissipation power 23.4 mW.     

A low power dissipation high-speed CMOS image sensor with column-parallel sigma–delta ADCs

A 60frames/s CMOS image sensor with column-parallel inverter-based sigma–delta (ΣΔ) ADCs is proposed in this paper. In order to improve the robustness of the inverter, instead of constant power supply, two buffers are designed to provide power supply for inverters. Instead of using of an operational amplifier, an inverter-based switch-capacitor (SC) circuit is adopted to low-voltage low-power ΣΔ modulator. Detailed analysis and design optimization are provided. Due to the use of the inverter-based ΣΔ ADCs, the conversion speed is improved while reducing the area and power consumption. The proposed CMOS image sensor has been fabricated with 0.18 μm CMOS process. The measurement results show that the random noise (RN) is 7e_rms⁻, the pixel conversion gain is 100 μV/e⁻. Since the measured full well capacity of the pixel is 25000e⁻, the CMOS image sensor achieves a 71 dB dynamic range (DR). The total power consumption at 60frame/s is 58.2 mW.     

恩平凹陷D区块韩江组沉积亚相特征分析

恩平凹陷新近系韩江组地层为海相三角洲沉积,砂体大面积发育,油气资源丰富。其南部D区块油气资源以钻井平台丛式井开发为主,井网不均匀,井资料少,沉积微相边界刻画难度大,需要在沉积环境特征分析的基础上确定沉积亚相类型,为后油气资源开采提供地质依据。本次研究充分利用岩芯、测井资料,分析了岩芯的矿物特征、结构特征、构造特征、生物特征,同时结合测井特征和砂体垂向韵律,得出研究区韩江组地层为辫状河三角洲前缘亚相,上述研究成果为后续重点层沉积微相精细刻画奠定基础。     

海拉尔盆地贝中油田南一段沉积微相特征

根据测井、岩心及实验分析资料,对海拉尔盆地贝中油田南一段进行了沉积微相分析并建立了相识别标志。利用沉积旋回特征,自上而下将南一段分为5个油层组。研究表明:贝中油田的沉积物源主要来自西南部;南一段发育扇三角洲前缘、滨浅湖等2种沉积亚相,其中扇三角洲前缘亚相可识别出水下分流河道、水下分流间湾、河口坝及席状砂等4种沉积微相,滨浅湖亚相可识别出坝砂、滩砂及浅湖泥等3种沉积微相;南一段I、Ⅱ油层组表现为2期水退、水进过程。     

隐性前积浅水曲流河三角洲地震沉积学特征——以渤海湾盆地冀中坳陷饶阳凹陷肃宁地区为例

以渤海湾盆地冀中坳陷饶阳凹陷肃宁地区为例,综合岩心、测井和三维地震综合解释资料,开展隐性前积浅水曲流河三角洲地震沉积学特征研究,并总结隐性前积浅水曲流河三角洲沉积模式。肃宁地区古近系沙一上亚段(Es1s)—东三段(Ed3)可识别出8个四级层序,反映湖平面周期性变化。从湖心向湖岸、从湖侵域向高位域,泥岩由灰色变为红色,显示湖水由深变浅。地震反射结构指示湖水变浅:Es1s(SQV3)叠瓦状前积厚度显示湖心水深40~60 m;随后叠瓦状前积结构消失,演变为亚平行结构(SQV4—SQV6),反射连续性逐渐变差,反映水深不超过30 m。岩心、测井曲线和地层切片分析揭示,与Es1s的SQV3叠瓦状前积浅水曲流河三角洲体系不同,Es1s的SQV4—SQV6为隐性前积浅水曲流河三角洲体系,地震沉积学响应特征主要为分带向湖盆中心推进的河道状和垛状地貌体系,指示分流河道和三角洲垛状体沉积。