Dynamic compaction properties of bentonite-based materials

Dynamic compaction tests of bentonite-based materials (BBMs) with 100, 70 and 50% bentonite contents have been performed using five powdery bentonites with different physicochemical properties to establish the simplified evaluation method for dynamic compaction properties of BBMs. For a given bentonite content and a total compaction energy condition, the maximum dry density, ρ_dmax, and the optimum water content, w_opt, which are well-known indexes of compaction properties, for BBMs were determined according to the type of bentonite used for BBMs. For evaluation of those values of BBMs derived in this study, the plastic limit of BBM, w_pbbm, was defined as the plastic limit that was measured using the sample pulverized to a maximum grain size of less than 425 μm in the case of BBM with sand having a maximum grain size of more than 425 μm and was measured using the powdery bentonite itself in the case of BBM without sand. This study proposed equations for evaluating ρ_dmax and w_opt of BBMs with more than 50% bentonite content under the total compaction energy conditions of 551–2755 kN-m/m³ using w_pbbm. Finally, we related the equations derived in this study to the equation for evaluating hydraulic properties of compacted BBMs proposed in previous work and proposed the preparation method of BBMs with more than 50% bentonite content for constructing BBM buffer by in-situ compaction method.     

Investigation of Kinnekulle K-bentonite aimed at assessing the long-term stability of bentonites under repository conditions

Müller-Vonmoos, M., Kahr, G., Bucher, F. and Madsen, F.T., 1990. Investigation of Kinnekulle K. bentonite aimed at assessing the long-term stability of bentonites under repository conditions. Eng. Geol., 28: 269–280.

The mineral formula, the content of fixed potassium and the average interlayer charge of the montmorillonite–illite mixed layer part of four Ordovician K-bentonite samples from Kinnekulle (Sweden) were investigated. The content of fixed potassium was found to decrease from 84% to 50% with increasing depth and distance from the Permian basalt intrusion about 100 m above the bentonite beds. The interlayer charge of the mixed layer is smectitic, i.e. below 0.5 charges per formula unit. The swelling pressures of air-dried, gently grinded and uniaxially compressed specimens with dry densities between 1.5 Mg/m³ and 2 Mg/m³ range from 1 N/mm² to 15 N/mm². This is about 20% of the swelling pressure values of identically treated Ca-montmorillonite. Following ultrasonic treatment, air-drying, gently grinding and compaction, increased swelling pressures of of about 70% of those Ca-montmorillonite were obtained. The reason for this increase in swelling pressure was investigated by dispersion experiments and determinations of water vapour adsorption isotherms of ultrasonically treated and untreated material.     

The distribution of radiogenic heat production as a function of depth in the Sierra Nevada Batholith, California

Geochemical analyses and geobarometric determinations have been combined to create a depth vs. radiogenic heat production database for the Sierra Nevada batholith, California. This database shows that mean heat production values first increase, then decrease, with increasing depth. Heat production is 2 μW/m³ within the 3-km-thick volcanic pile at the top of the batholith, below which it increases to an average value of 3.5 μW/m³ at 5.5 km depth, then decreases to 0.5–1 μW/m³ at 15 km depth and remains at these values through the entire crust below 15 km. Below the crust, from depths of 40–125 km, the batholith's root and mantle wedge that coevolved beneath the batholith appears to have an average radiogenic heat production rate of 0.14 μW/m³. This is higher than the rates from most published xenolith studies, but reasonable given the presence of crustal components in the arc root assemblages. The pattern of radiogenic heat production interpreted from the depth vs. heat production database is not consistent with the downward-decreasing exponential distribution predicted from modeling of surface heat flow data. The interpreted distribution predicts a reasonable range of geothermal gradients and shows that essentially all of the present day surface heat flow from the Sierra Nevada could be generated within the 35 km thick crust. This requires a very low heat flux from the mantle, which is consistent with a model of cessation of Sierran magmatism during Laramide flat-slab subduction, followed by conductive cooling of the upper mantle for 70 m.y. The heat production variation with depth is principally due to large variations in uranium and thorium concentration; potassium is less variable in concentration within the Sierran crust, and produces relatively little of the heat in high heat production rocks. Because silica content is relatively constant through the upper 30 km of the Sierran batholith, while U, Th, and K concentrations are highly variable, radiogenic heat production does not vary directly with silica content.     

开采状态下河北平原孔隙热储地热水资源的构成——以辛集集中开采区为例

地热水属于承压水,其储存量包括容积储存量和弹性储存量两部分,当水位处于含水层顶板以上时,已开采出的地热水只能是弹性储存量。在河北平原区进行区域地热资源评价时,地热水可开采量按照开采系数法、解析法等不同方法计算,与弹性储存量存在巨大差距。为研究地热水开采资源的构成并更加准确评价集中开采区地热水的可开采量,采用地下水均衡法对辛集集中开采区地热水开采资源量进行了计算,结果显示: 侧向补给量为126×10⁴ m³,占开采资源量的60.9%; 越流补给量为19.7×10⁴ m³,占开采资源量的9.55%; 弹性释水量为33.1×10⁴ m³,占开采资源量的16.1%; 弱透水层压密释水量为27.4×10⁴ m³,占开采资源量的13.3%。研究结果说明,集中开采区地热水的开采资源量不仅仅来自于热储层的弹性释水量,还包括侧向补给量、越流补给量和弱透水层的压密释水量。研究成果对于科学合理地开发地热资源、更好地遏制和缓解地热水开采引发的地质环境问题具有一定意义。     

Variation in element release rate from different mineral size fractions from the B horizon of a granitic podzol

Far-from-equilibrium batch dissolution experiments were carried out on the 2000–500, 500–250, 250–53 and 53–2 μm size fractions of the mineral component of the B horizon of a granitic iron humus podzol after removal of organic matter and secondary precipitates. The different size fractions were mineralogically and chemically similar, the main minerals present being quartz, alkali and plagioclase feldspar, biotite and chlorite. Specific surface area increased with decreasing grain size. The measured element release rates decreased in the order 53–2>>>2000–500>500–250>250–53 μm. Surface area normalised element release rates from the 2000–500, 500–250 and 250–53 μm size fractions (0.6–77×10⁻¹⁴ mol/m²/s) were intermediate between literature reported surface area normalised dissolution rates for monomineralic powders of feldspar (0.1–0.01×10⁻¹⁴ mol/m²/s) and sheet silicates (100×10⁻¹⁴ mol/m²/s) dissolving under similar conditions. Element release rates from the 53–2 μm fraction (400–3000×10⁻¹⁴ mol/m²/s) were a factor of 4–30 larger than literature reported values for sheet silicates. The large element release rate of the 53–2 μm fraction means that, despite the small mass fraction of 53–2 μm sized particles present in the soil, dissolution of this fraction is the most important for element release into the soil. A theoretical model predicted similar (within a factor of <2) bulk element release rates for all the mineral powders if observed thicknesses of sheet silicate grains were used as input parameters. Decreasing element release rates with decreasing grain size were only predicted if the thickness of sheet silicates in the powders was held constant. A significantly larger release rate for the 53–2 μm fraction relative to the other size fractions was only predicted if either surface roughness was set several orders of magnitude higher for sheet silicates and several orders of magnitude lower for quartz and feldspars in the 53–2 μm fraction compared to the other size fractions or if the sheet silicate thickness input in the 53–2 μm fraction was set unrealistically low. It is therefore hypothesised that the reason for the unpredicted large release rate from the 52–3 μm size fraction is due to one or more of the following reasons: (1) the greater reactivity of the smaller particles due to surface free energy effects, (2) the lack of proportionality between the BET surface area used to normalise the release rates and the actual reactive surface area of the grains and, (3) the presence of traces quantities of reactive minerals which were undetected in the 53–2 μm fraction but were entirely absent in the coarser fractions.     

Engineering-geological mapping of tropical soils for land-use planning and geotechnical purposes: A case study from Jamaica, West Indies

An area of a Tertiary and Cretaceous deposits, 100–310 m above sea level and on predominant 20–45°, highly dissected, concave slopes was investigated to assess its geotechnical characteristics and land use planning implications. Lithologies include turbidites, fluvial conglomerates, breccias, sandstones, mudrocks, carbonates, granodiorite, acid dykes, chloritized and epidotized volcanics, andesite and Holocene fluvial deposits. Bedrock is highly fractured and sheared, hydrothermally altered and highly weathered. Soils are quite variable, with a strong geological control on soil properties. Soils are generally sandy to gravely, with local silts and clays in mudrocks, within Holocene alluvium or in hydrothermally altered and sheared granodiorites. The soils are composed of 0.14–80.00% gravel; 5.36–62.50% sand, 2.33–50.55% silt, 0.17–51.50% clay, and total fine content between 2.50 and 94.50%, with natural moisture between 4 and 44% during the dry season, plastic limit between 6 and 35%, liquid limit between 19 and 83% and plasticity index between 1 and 59%. Sandy soils have residual friction angles between 19 and 39°, PI values less than 35% with cohesion between 1.00 and 5.27 KN/m² for cohesive samples. ASTM classification of soils include soil groups GC, GM, GW, GP, SP, SM, SC, SM, SC, ML, CL and CH.

Based on the characteristics of the terrain, the geotechnical and land use planning problems include high landslide frequency and susceptibility, soil erosion, fluvial and reservoir sedimentation, high debris flow hazard, cut slope failures, potentially expansive clays and silts, seepage erosion and soil piping, differential settlement in interlayered competent and incompetent lithologies, high solution erosion and potential subsidence over limestones, waste water disposal problems and groundwater pollution and seismic induced settlement and ground failures. These phenomena suggest that systematic site investigations should be conducted prior to the utilization of these areas for construction and development in order to minimize the deleterious effects resulting from ground failure.     

Geotechnical properties and behaviour of Nigerian tar sand

A brief review of the geology of the tar sand areas of Nigeria is given. Analysis shows that the tar sand used for the tests consists of a well graded silty sand (cmf) with about 5% clay; and 3–5% bitumen. Results presented show a very high in situ compressive strength of about 450 kN/m², a high ratio of tensile to compressive strength of about 22%, peak shear strength parameters of C_p′=15kN/m²and φ_p′ = 19° and residual parameters of C_r =0, φ_r = 18°. The compacted tar sand behaved like an overconsolidated soil with a preconsolidating pressure, P_c of 140 kN/m2. In general, the results of the in situ strength tests indicate that the Nigerian tar sand behaved as a soft sandstone.     

北京延庆地区南湾道豁子沟泥石流发育特征

以北京市延庆地区南湾道豁子泥石流沟为研究对象,通过野外泥石流沟精细调查及历史资料统计,详细了解该泥石流发育特征和形成条件,针对流域内松散堆积物补给条件进行重点分析;综合研究该泥石流的动力学特征,进行泥石流危险区预测评价,提出相应的防治措施建议。研究结果表明:该泥石流沟内松散堆积物动储量为18.47×10⁴ m³,分为冲洪积、残坡积、人工堆积和崩滑塌等4种补给来源,其中冲洪积和残坡积所占比重最大;泥石流发展阶段处于衰退期;经动力学分析,洪峰流量值在10年一遇的降雨条件下为52.53 m³/s,20年一遇的降雨条件下为59.25 m³/s,50年一遇的降雨条件下为68.13 m³/s,100年一遇的降雨条件下为74.85 m³/s,对应的一次固体冲出总量分别为0.77×10⁴ m³、0.87×10⁴ m³、1.00×10⁴ m³和1.10×10⁴ m³;属于中型泥石流,最大危险区面积为0.238 3 km²。通过评价分析,该泥石流沟仍存在爆发中型泥石流的可能性,将对下游南湾村以及千沙公路行车和行人的生命财产安全造成威胁。研究成果可为延庆地区该类泥石流单沟预警模型研究和灾害防治提供科学依据。     

黔北正安地区五峰组—龙马溪组页岩气地质特征及有利区预测

为明确黔北正安地区上奥陶统五峰组至下志留统龙马溪组的页岩气地质特征,充分应用页岩气地质调查、重磁电、二维地震、地质调查井及测试分析等工作方法,开展黔北正安地区1:5万页岩气基础地质调查,对五峰组至龙马溪组富有机质页岩的分布、沉积环境、有机地球化学、岩石矿物、储集性能及含气性等特征进行分析研究,结果表明: 研究区五峰组—龙马溪组富有机质页岩为深水陆棚相沉积,主要分布有安场向斜、斑竹向斜和泥高向斜,厚度14.5~55 m,埋深0~3 200 m; 有机碳(TOC)含量1.0%~4.0%,有机质镜质体反射率(R_o)为1.82%~2.23%,有机质类型以Ⅰ型干酪根为主; 岩石主要由石英、长石和黏土矿物组成,脆性矿物含量高,一般大于50%; 孔隙度为2.03%~3.89%,渗透率为0.35×10^-5~1.86×10^-5μm²,表现为低孔、特低渗的特征; 最高含气量为2.88 m³/t,显示出较好的含气性特征。综合分析和评价圈出3个页岩气聚集有利区,分别为安场区块、斑竹区块和泥高区块,这为研究区页岩气进一步勘探开发指明了方向。     

Geological characteristics and favorable areas prediction of shale gas in Wufeng-Longmaxi Formation in Zheng’an area of Northern Guizhou

In order to determine the shale gas geological characteristics of Wufeng Formation in upper Ordovician and Longmaxi Formation in Lower Silurian of Zheng'an area in Northern Guizhou, the authors used geology survey,gravity,magnetic,two dimensional seismic,geological well and test analysis methods to carry out 1:50000 shale gas basic geology survey. The distribution, depositional environment, organic geochemical, mineral composition, reservoir properties and hydrocarbon content and other characteristics of Wufeng-Longmaxi Formation rich organic shale were obtained. The results show that the rich organic shale belongs to deep water continental shelf facies, mainly distributed in Anchang, Banzhu and Nigao syncline, with a thickness of 14.5-55 m and burial depth of 0-3 200 m. The TOC content is between 1.0% and 4.0%, and the vitrinite reflectance (R_o) is between 1.82% and 2.23%, with the organic matter type mainly I kerogen. The rocks are mainly composed of quartz, feldspar and clay minerals. The brittle mineral content is high, generally more than 50%. The porosity is generally between 2.03% and 3.89%,and the permeability is generally between 0.35×10^-5 μm² and 1.86×10^-5 μm², showing the characteristics of low porosity and low permeability. The highest gas content is 2.88m³/t, showing good gas content characteristics. Three favorable target areas for the shale gas in Zheng’an area were identified through comprehensive analysis and evaluation optimization, that is Anchang,Banzhu and Nigao block respectively, which provides exploration direction for shale gas exploration and development in the study area.     

Thermodynamics of U(VI) sorption onto Shewanella putrefaciens

We have conducted acid–base potentiometric titrations and U(VI) sorption experiments using the Gram negative, facultatively anaerobic bacterium Shewanella putrefaciens. Results of reversed titration studies on live, inactive bacteria indicate that their pH-buffering properties result from the equilibrium ionization of three discrete populations of functional groups. Carboxyl (pK_a=5.16±0.04), phosphoryl (pK_a=7.22±0.15) and amine (pK_a=10.04±0.67) groups most likely represent these three resolvable functionalities, based on their pK_a values. Site densities for carboxyl, phosphoryl and amine groups on the bacterial surface were approximately 31.7 μmol sites/g bacteria (0.35±0.02 sites/nm²), 8.95 μmol/g (0.11±0.007 sites/nm²) and 38.0 μmol/g (0.42±0.008 sites/nm²), respectively, based on an estimated bacterial specific surface area of 55 m²/g. Sorption experiments showed that U(VI) can reversibly complex with the bacterial surface in the pH 2–8 interval, with maximum adsorption occurring at a pH of 5. Sorption is not strongly sensitive to ionic strength (NaCl) in the range 0.02–0.10 M. The pH and ionic strength dependence of U(VI) sorption onto S. putrefaciens is similar to that measured for metal-oxide surfaces and Gram positive bacteria, and appears to be similarly governed by competitive speciation constraints. Measured U(VI) sorption is accounted for by using two separate adsorption reactions forming the surface complexes >COO–UO₂⁺ and >PO₄H–UO₂(OH)₂. Using S. putrefaciens as a model organism for dissimilatory metal-reducing Gram negative anaerobes, our results extend the applicability of geochemical speciation models to include bacteria that are capable of reductively solubilizing or precipitating a wide variety of environmentally and geologically important metals and metallic species.     

The Kostanjek landslide in Zagreb

The large landslide, Kostanjek, on the southern slopes of the mountain, Zagreba ka Gora, in the western suburb of Zagreb was activated in 1963 after some 2.1 × 10⁶ m³ of marl for the cement factory, Croatia, was excavated at the foot of the slope. The geological features (sinclinal structure, faults, hydrogeological conditions, extension of the “Tripoli” marl strata) which had an important role in the formation of the slide, as well as the means of marl exploitation by means of mass blasting, are presented in the paper. The Kostanjek slide involves an urbanized area of some 100 ha. It is estimated that a sliding mass of some 32 × 10⁶ m³ is involved, with a maximum depth of 90 m. Sliding occurs in three levels. The displacements of the surface are 3–6 m. The excavation of marl was stopped in 1988, when a total of 5.3 × 10⁶ m³ of material was excavated. Since then the magnitude of surface displacement per year has decreased. The Kostanjek slide is still active. It is estimated that natural stabilization will take a long time, probably decades. Analyses of possible measures for the stabilization of movements suggested that preventive drainage with continuous observation of the slide is most suitable.     

The influence of the geological and geomorphological settings on shallow landslides. An example in a temperate climate environment: the June 19, 1996 event in northwestern Tuscany (Italy)

On June 19, 1996, an extremely heavy rainstorm hit a restricted area in the Apuan Alps (northwestern Tuscany, Italy). Its max intensity concentrated over an area of about 150 km² astride the Apuan chain, where 474 mm was recorded in about 12 h (21% of the mean annual precipitation, with an intensity up to 158 mm/h). The storm caused floods and hundreds of landslides and debris flows, which produced huge damage (hundreds of millions of Euros), partially destroyed villages and killed 14 people. This paper reports the results obtained from a detailed field survey and aerial view interpretation. In the most severely involved area, 647 main landslides were investigated, mapped and related to the geologic, geomorphic and vegetational factors of the source areas. This was in order to define the influence of these factors and contribute to an evaluation of the landslide hazard in the study area. An assessment was also made of the total area and volume of material mobilised by landsliding. The study area, about 46 km² wide, includes three typically mountainous basins, characterised by narrow, deep cut valleys and steep slopes, where many rock types outcrop. Most of the landslides were shallow and linear, referable to complex, earth and debris translational slide, which quickly developed into flow (soil slip–debris flow). Usually, they involved colluvium and started in hollows underlain by metamorphic rock (metasandstone and phyllite), often dipping downslope. Therefore, bedrock lithology and impermeability appeared to be important factors in the localisation of the landslide phenomena. The investigation of the geomorphic and land use features in the source areas also frequently highlighted a rectilinear profile of the slope, a high slope gradient (31–45°) and dense chestnut wood cover. In the area, about 985,000 m² (2.1% of 46 km²) was affected by landsliding and about 700,000 m² of this area was covered by chestnut forest. The landslides removed about 7000 trees. The volume of mobilised material was about 1,360,000 m³; about 220,000 m³ remained on the slopes, while the rest poured into the streams. In addition, about 945,000 m³ was mobilised by the torrential erosion in the riverbeds.     

河西走廊疏勒河流域出山径流变化规律及趋势预测

依据甘肃省河西走廊疏勒河流域1956-2013年水文站实测及水文调查资料, 对流域出山径流的年内、年际变化进行统计分析, 并用坎德尔秩次相关法等检验流域径流变化趋势. 结果表明: 1956-2013年多年平均出山径流量为11.6679×10⁸ m³; 汛期集中在6-9月, 各河流来水量占年来水量的35.9%~78.7%; 地下水补给平均占径流量的40.46%; 出山径流年际变化相对稳定, 趋势表现为持续性上升的特点. 未来2014-2018年疏勒河干流出山径流为偏丰, 年平均径流量预计为13.01×10⁸ m³.     

细粒土含量对粗粒硫酸盐渍土路基填料盐胀特性的影响试验及分析模型

为了明确细粒土含量对粗粒硫酸盐渍土路基填料盐胀量的影响,针对 1% 和 3%含盐量工况下的砂、砾类盐渍土,采用降温试验研究了细粒土含量递增条件下粗粒硫酸盐渍土的盐胀特点。在此基础上,利用 PFC^3D技术模拟了粗粒盐渍土的盐胀变形并分析其机制,结合微观试验分析了盐胀状态中粗粒土骨架典型状态。结果表明：随着细粒土含量的增加,粗粒硫酸盐渍土的盐（冻）胀量均先增加后减少再增大,分界细粒土含量因含盐量及土类不同而异,1%、3% 含盐量的砂、砾类土样分别在15%和10%细粒土含量时产生最大盐（冻）胀量;3%含盐量砂、砾类土的起始盐胀温度约 20 ℃,1%含盐量土样的起始盐胀温度随细粒土含量及土种类不同差异较大且存在明显的界限细粒土含量,当细粒土含量低于界限值时土体的起始盐胀温度约为0.5～2 ℃,高于界限值时土体的起始盐胀温度约为 4～12 ℃;同时提出了盐胀状态中粗粒土骨架典型状态模型及其作为路基填料的细粒土含量界限值。     

Horizontal frost heave thrust acting on buttress constructions

Frost heave thrust of soil varies with its water content. When the water content of the soil is less than its plastic limit, the horizontal frost heave thrust of soil does not appear. When the water content of the soil is greater than its plastic limit the frost heave thrust increases with increasing water content and when the water content is a little over its liquid limit, it reaches a maximum value.

Also, the horizontal frost heave thrust of soil varies with temperature. It increases as the negative temperature falls, until it reaches a maximum value at about −7°C.

It should be noted that the distribution of the horizontal frost heave thrust along the lateral surface of the structure is not always uniform: its value is greatest at the middle, less at the bottom, and least at the top. The maximum value generally appears at the place where the depth is about 60–80% of the depth of frost penetration.

According to laboratory data and engineering practice, the values of horizontal frost heave thrust vary greatly, but its maximum value is generally about 4.1–4.2 kg/cm².     

火山碎屑岩的储层物性——以松辽盆地营城组为例

对松辽盆地营城组35口盆内深层钻井和2口剖面浅钻全取心井的对比研究揭示：在浅层（埋深<500 m）,火山碎屑岩储层物性（平均孔隙度18.7%、渗透率0.32×10^-3μm²）好于熔岩（14.0%,0.18×10^-3μm²）;在深层（埋深>2 800 m）,火山碎屑岩物性（2.6%,0.05×10^-3μm²）明显差于熔岩（7.3%,0.07×10^-3μm²）。熔岩和火山碎屑岩的储层物性总体上都随埋深增加而变差,但火山碎屑岩的变化率显著大于熔岩;所以当大于一定埋深（2 500~3 000 m）时,熔岩的物性优于火山碎屑岩而成为主力储层。熔岩与火山碎屑岩物性随埋深变化的差异主要源于它们成岩方式的不同：前者冷凝固结,骨架体积受压实影响很小;后者压实固结成岩,其特点同沉积岩。在中浅层勘探中（埋深小于2 500 m）火山碎屑岩可作为重点目标。     

鄂尔多斯盆地陇东地区延长组长82优质储集层成因机理研究*

鄂尔多斯盆地陇东地区长8₂储集层平均孔隙度为8.8%,平均渗透率为0.64×10^-3μm²,属于低孔低渗储集层。强烈的压实作用是储集层物性变差主要原因,碳酸盐胶结作用促使储集层物性进一步变差。尽管储集层物性整体较差,但在普遍低孔低渗背景下仍发育相对高孔渗的优质储集层。对优质储集层进行了分析,总结了优质储集层的典型特征,统计表明:优质储集层的塑性组分含量较低,孔隙类型以绿泥石胶结残余粒间孔和溶孔为主,孔隙结构以中小孔—中细喉为主。在此基础上,分析了优质储集层成因机理。研究认为:分流河道、河口坝等微相高能厚层砂体有利于优质储集层发育,相对低的塑性组分含量和绿泥石环边胶结有利于粒间孔隙的保存,溶蚀作用是次生孔隙形成的最主要成岩作用。     

超压背景下中深层砂岩储集层沉积—成岩演化差异性分析: 以南海莺歌海盆地中新统黄流组为例*

南海莺歌海盆地内地层普遍发育超压,东方区和乐东区是莺歌海盆地天然气成藏有利区的核心地带。其中,东方区位于底辟带中心,超压形成时间较早(9—5 Ma),主要物源来自西部昆嵩隆起区;乐东区位于莺东斜坡带,超压形成时间较晚(5—2 Ma),主要物源区为东部海南隆起区。本研究通过铸体薄片、荧光薄片、扫描电镜、电子探针、含烃包裹体微束荧光分析、流体包裹体激光拉曼成分与均一温度、X射线衍射黏土矿物等分析测试研究方法,对东方区和乐东区超压背景下黄流组砂岩储集层的岩石学与物性特征、烃类充注与成岩作用特征进行对比分析。结果显示: (1)东方区黄流组砂岩的压实作用、胶结作用较弱,物性较好(平均孔隙度17.68%,平均渗透率11.11×10^-3 μm²),处于中成岩A期晚期;乐东区黄流组砂岩整体压实作用、胶结作用较强,物性较差(平均孔隙度8.94%,平均渗透率1.52×10^-3 μm²),处于中成岩B期。(2)研究区储集层物性主要受沉积作用、超压背景和成岩作用的控制。物源、沉积中心与沉降中心、沉积相类型,超压形成时间和烃类充注规模共同影响了储集层的成岩作用特征及成岩—孔隙演化过程。(3)超压在一定程度上抵抗了压实作用强度,抑制了胶结作用,促进了溶蚀作用。