川中地区中上寒武统洗象池组颗粒滩储集层特征及主控因素*

川中地区中上寒武统洗象池组油气勘探一直未取得大规模突破,仅在威远—资阳地区获得了少量产能,研究其储集层形成过程和主控因素可以为勘探提供更可靠的地质依据。本研究基于川中地区的野外露头、岩心、薄片和钻测井等地质资料,对川中地区洗象池组储集层特征进行了详细的研究,在此基础上分析了不同类型颗粒滩沉积组合、准同生溶蚀作用和表生岩溶作用对储集层的影响。结果表明: (1)研究区洗象池组储集岩主要为颗粒白云岩,根据原始结构保存程度,可将颗粒白云岩划分为残余颗粒白云岩和粉晶—细晶白云岩,储集空间以粒间溶孔、晶间溶孔及小型溶洞为主,整体表现为低孔低渗的特征;(2)研究区洗象池组发育潟湖—颗粒滩(—台坪)、颗粒滩—台坪(混积潮坪)、多期颗粒滩垂向叠置3种颗粒滩沉积组合类型,其中多期颗粒滩垂向叠置可形成厚度较大的颗粒岩段,其储集层物性最好;(3)准同生溶蚀作用是川中洗象池组储集层形成的关键,加里东期表生溶蚀作用改善了储集层质量。     

长江河口水下沙洲类型及典型水下沙洲的推移规律

对长江河口水下沙洲的类型及其演变规律进行了研究,把水下沙洲分为 4 种基本类型：节点型沙洲、弯道型沙洲、涨落潮流分异型沙洲、分汊口型沙洲。并研究了河口区若干典型沙洲在最近 20 a 的推移规律和冲淤状况,对沙洲冲淤量进行了计算,结果表明河口水下沙洲冲淤频繁, 1991 年后仅上、下新浏河沙 5 m 等深线内沙体每年冲淤量达 1.5×106 t,尤其是 1998 年大洪水导致上新浏河沙被冲失近 1/3 。     

扬子浅滩沙波底形活动性评估

扬子浅滩位于长江口以东,水深40 m左右,普遍发育中小水下沙丘并处于运动状态。按32片沙波参数统计,迁移方向在90°~180°之间,其中150°~180°者占30%,120°~150°者占69%;使用Rubin和改进的Hardisty公式计算,以潮流作用为主的常态海况下,沙波迁移率为19.70 m/a,以浪流为主的暴风浪期间,约为12.72 m/a,一年总迁移率约为32.4 m/a,与世界上若干海底沙波定位观测数据相对比,这一迁移率应属于缓慢—中等的量级。     

九段沙上沙南沿坍塌与外沙内泓效应

利用1986~2013年的长江口海图以及2013年九段沙上沙南沿的冲淤观测数据,分析了外沙内泓地形形成机理以及凸显的效应。长江口深水航道治理工程改变了九段沙湿地局部边界条件,导致江亚南沙沙尾下延,深泓线北移,上沙南沿坍塌后退。建议采取护滩工程措施,保护上沙湿地资源。     

基于多目标决策模型的如东近岸浅滩适宜围填规模研究

适宜的围填海规模能够最大限度的协调岸滩围填和海洋资源环境保护的关系。以江苏辐射沙脊海域如东近岸浅滩围填海为例,运用多目标决策理论与方法,综合考虑围填海对动力泥沙环境、海洋生态环境、资源综合开发和社会经济影响,建立围填海适宜规模评价指标体系,构建适宜围填规模评价决策模型。并对该岸段不同的围填规模方案进行计算,据此推荐围堤前沿线位于+5 m的围填海方案是该岸段的适宜围填规模。对围填海适宜规模的研究手段和方法进行了探索和尝试。提出的研究方法及推荐的如东岸段近岸浅滩适宜围填规模可为江苏滩涂资源的开发提供参考。     

Sedimentary Facies and Distribution of Reservoir Rocks from the Feixianguan Formation in the Daxian-Xuanhan Region, NE Sichuan

The Lower Triassic Feixianguan Formation in the Daxian-Xuanhan region, northeastern Sicbuan is interpreted to be a carbonate platform intermediate between the West Hubei-East Cbongqing marine basin and Guangyuan-Wangcang marine basin. Outcrops, well logs and seismic data have disclosed that three sedimentary facies can be identified for the formation： open platform, platform exposed shoal and restricted platform facies. During the early stage of deposition of the Feixianguan Formation, there existed a sedimentary framework all the same as the Late Permian one： open platform in the west, and platform exposed shoal, restricted platform and open platform eastwards. The gradual increase of the shoal area permitted eastward migration of the shoal facies. During the deposition of the third member of the Feixianguan Formation, the study area was invaded by temporary transgressions. Till the deposition of the fourth member of the formation, the study area was prevailed over the unified restricted platform deposits, as indicated by the sedimentary model for the typical carbonate platform shoal deposits. The reservoir rocks in the Feixianguan Formation consist mostly of solution opening dolostone, and the rock types are assembled by oolitic dolostone, residual oolitic dolostone and sucrosic residual oolitic medium- to coarse-grained dolostone. The deep and shallow dual laterologs show relatively high resistivity, clear amplitude differences and time difference saltation of acoustic waves in some intervals. The seismic responses are indicated by low-frequency and highly variable amplitudes and chaotic reflection configurations. The reservoir rocks are characterized by high porosity-high permeability and medium porosity-medium permeability, showing a marked correlation between porosity and permeability. Solution openings are extremely developed in the reservoir rocks, including cast pores, intergranular solution openings, intercrystal pores, intercrystal solution openings, solution openings （caves） and minute fissures. Macropores and coarse pore throats are common. The reservoir rocks are apparently controlled by sedimentary facies in distribution patterns. Vertically, they occur dominantly in the second and first members of the Feixianguan Formation, and laterally in the platform exposed shoals and restricted platforms, where good natural gas potential is expected.     

川中龙岗地区下侏罗统大安寨段沉积相分析及有利储集层预测

应用钻井、测井和地震等资料对川中龙岗地区下侏罗统大安寨段的沉积相类型及其展布特征进行了研究,将大安寨段的湖泊相沉积划分为4个亚相及若干微相。大安寨段沉积时期的沉积展布及演化主要受湖平面升降控制,经历过一次较大规模的水进水退旋回:大三沉积时期发生水进,主体为浅湖—半深湖沉积;大一三沉积时期水体最深,主体为半深湖沉积;大一三沉积晚期发生水退,到大一沉积晚期湖平面已降至较低水平,主体为滨浅湖沉积,介壳灰岩发育。沉积相带在平面上具有明显的环带状展布特征,据此建立了大安寨段沉积模式。大一段主要发育5个介壳滩,是最有利于储集层发育的沉积相带。储集岩类型主要为介壳灰岩和泥质介壳灰岩,结合裂缝发育分析,预测了3个有利储集层区带。     

陕西省华阴、潼关渭河滩区地下水特征及动态研究

华阴、潼关渭河滩区地下水丰富,水位埋藏浅,地表水渭河和它的补排关系,地下自身补给、排泄和径流规律、多年动态特征以及水质状况,是本篇论文研究的重点。摸清以上地下水的特征和规律,对华阴、潼关渭河滩地区地下水开发利用前景,分析对当地的经济发展具有现实意义。     

曹妃甸开发布局与滩槽格局协调性研究

渤海湾曹妃甸近岸海区多个潮汐深槽与沙岛相伴而生并构成极为复杂的海岸动力地貌体系,而维护既有的滩槽宏观格局是保持滩槽稳定与合理开发布局的重要基础。曹妃甸开发遵循因势利导的原则,对浅滩与深槽进行了科学保护和合理利用,通过寻找深水岸线开发、滩涂匡围与环境影响之间的平衡点,在开发合理规划布局与维护滩槽动力地貌格局现状之间实现了很好的协调性。工程实践效果表明,由于曹妃甸开发布局规划科学合理,没有改变整个海区的滩槽动力地貌格局和潮汐深槽形成的动力机制,因而深槽及周边海区在开发工程实施后稳定性良好。     

The Major Controlling Factors and Different Oolitic Shoal Reservoir Characteristics of the Triassic Feixianguan Formation,Eastern Longgang Area,NE Sichuan Basin,SW China

Based on comprehensive analyses of occurrence, petrological observation, pore structure and geochemistry, the different reservoir characteristics and reservoir evolutionary pathways between different oolitic shoal reservoir types of the Feixianguan Formation on the west side of the Kaijiang-Liangping Trough have been studied. There exist three stages of high-energy slope break belts in the Feixianguan period, the corresponding three stages of oolitic shoals gradually migrating in the direction of the trough. Three types of oolitic shoal reservoirs, namely, residual-oolitic dolomite, mold-oolitic dolomite and sparry oolitic limestone, were formed during sedimentary-diagenetic evolution, the pore types being intergranular dissolved pore, mold pore (or intragranular dissolved pore) and residual intergranular pore, respectively. The petrology, physical properties and pore structure of the different types of oolitic shoal reservoirs are quite different. Residual-oolitic dolomite reservoirs have the best quality, while sparry oolitic limestone reservoirs have the poorest. Combined with analyses of trace elements, rare earth elements and carbon-oxygen isotopes, it is suggested that the formation of residual-oolitic dolomite reservoirs is jointly controlled by penesaline seawater seepage-reflux dolomitization and hydrothermal dolomitization. Mold-pore oolitic dolomite reservoirs are controlled by penesaline seawater seepage-reflux dolomitization and meteoric water solution. The burial dissolution of organic acid not only further improves the reservoir qualities of previously formed oolitic dolomite reservoirs, but also preserves residual intergranular pores in the sparry oolitic limestone reservoirs.