Baoziwan-Majiashan Area of Jiyuan Oilfield Analysis of Reservoir Characteristics and Main Control Factors in Long 4 5 Section

Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10−3 µm2. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir.

Physical property characteristics of Yanchang Formation reservoir in the southwest of Ordos Basin and their controlling fac-tors： taking Chang 3 and Chang 4 ＋ 5 reservoirs in Longdong area as an example

分析鄂尔多斯盆地西南部陇东地区延长组储层物性特征及其控制因素，发现沉积和成岩控制储层物性。沉积微相带不同，储层物性就不同；成岩作用中压实-压溶作用、胶结作用对储层物性具有破坏作用，溶蚀作用是储层物性改善的关键因素。沉积微相带是控制油气藏储层展布的内在因素，成岩作用是储层形成过程中控制物性演化的外部因素。

Effect of Flood Peak Discharge Control by a Small Reservoir in an Urbanized Area—Case Study in the Kurabe River Basin, Japan

Recently severe damage of flooding by urbanization was frequently occurred. To prevent this damage, small reservoir was constructed in the urbanized residential area. This paper describes an effect of flood peak discharge control by a small reservoir (control reservoir) caused by rapidly developed urbanization. Although work for this purpose was conducted, research on the effects of the control reservoir was not conducted until now. This research, conducted by simulation, was a case study in the Kurabe River Basin in the Tedori River Alluvial Fan Area, Japan, based on the precise investigation of the reservoir in the actual field. The study was conducted to determine not only the actual control reservoir capacity for the newly developed residential area but also the ideal capacity for all present residential areas and the largest capacity allowable for a maximum rainfall event that recently occurred. The control reservoir effects between individual blocks and the entire basin area were compared by dividing the test basin into 15 blocks (sub-basins). The results showed that the effects on the capacity per unit area of the residential area in blocks have close relationship with the decreasing ratio of peak discharge in blocks. Consequently, the effects of control reservoir capacity and the limitation were clarified. In the future, control reservoirs should be constructed for all of the already developed residential areas, for example, by utilizing underground car parking lot. The results of this research can contribute to the design of the control reservoir for protection against flooding damage in urbanized areas.

Characteristics of Mesozoic-Cenozoic tectonic diagenesis in the Kuqa area of the Tarim Basin,China

Tectonic diagenesis is a common and important geological phenomenon. We can fully understand the diagenesis of compressional basins through studying tectonic diagenesis. In this paper, we presented the tectonic diagenetic characteristics in the Kuqa area of the Tarim Basin by integrated method of geological analysis and paleotectonic stress. The results showed that the Mesozoic-Cenozoic tectonic diagenesis affected sandstone compaction evolution mainly through physical mechanisms. It showed characteristics of abrupt change and nonthermal indicator (it means that sandstone compaction can not be explained by thermal diagenetic compaction alone because actual sandstone compaction was larger than thermal compaction), which were different from the thermal and fluid diagenesis. Compared with thermal diagenesis, tectonic diagenesis had a typical tectonic compaction in very short time, and many phases of tectonic deformation showed multiple abrupt changes of compaction. There are obvious differences between tectonic and thermal diagenetic compaction, leading to sandstone compaction being larger than the thermal compaction under the same thermal evolution stage in the areas where tectonic deformation happened. The stronger the tectonic deformation, the more obvious the difference. Tectonic process changed the stress distribution through changing the tectonic deformation styles, resulting in different tectonic diagenesis effects. Therefore, tectonic diagenesis of Mesozoic-Cenozoic in the Kuqa area can be divided into four types including rigid rock restraint, fault ramp, low angle fault slippage, and napping.

Measurement of the Effective Dose Radiation at Radiology Departments of Some Hospitals in Duhok Governorate

During operating of the X-ray machines, if the protection of X-ray rooms is insufficient, not only the patient but also clinical staffs as well as public are exposed to high X-ray dosage and they are affected from X-ray related to the dose level. In the present survey, by testing the radiological leakage and scatter from X-rays machines in radiology departments of 7 randomly selected hospitals in Duhok governorate, the effects dose of X-ray to the both control panel area and the patients waiting or visiting area who are located near the radiography room, were measured. The dose was recorded for a range of peak kilovoltage (kVp) and mAs values to find efficiency of shielding materials (barriers) of radiography rooms for different X-rays level. The measurements were performed at one meter above the ground surface which was the same height of X-rays tube by using Gamma Scout dosimeter. From the measurement results, it was seen that the most hospitals barriers (doors and walls) were not appropriate to the standards except 2 hospitals. The maximum effective doses were measured in uncontrolled area of Khazer hospital which was 82.48 ± 0.73 mSv·yr-1 that was much more than the reference dose limits and in controlled area of Haval Banda Zaroka hospital which was 12.98 ± 0.16 mSv·yr-1. In result, the knowledge about the radiation dose affecting the radiologists and public in the selected hospitals was obtained, and by informing the radiologists and the hospitals managements, the necessary regulations would be planned.

Production characteristics and sweet-spots mapping of the Upper Devonian-Lower Mississippian Bakken Formation tight oil in southeastern Saskatchewan, Canada

A workflow that helps identify potential production sweet spots in the Middle Bakken tight oil play is proposed based on analysis of large amounts of production data. The proposed approach is a multivariate statistical model that extracts relevant information from a training dataset of production wells to facilitate geological similarity comparison between economic and sub-economic production wells. The model is applied to the Middle Bakken tight oil play in southeastern Saskatchewan. Data screening for diagnostic geological indicators for sweet spots reveals that several geological factors indicative for conventional oil reservoirs seem to work for the Middle Bakken tight oil play as well. These factors include: a) the NE Torqunay-Rocanville Trend serving as a preferred regional migration path for connecting mature source rock in southern Williston Basin and the Middle Bakken tight reservoir in southeastern Saskatchewan; b) the oils in the Bakken tight reservoirs along the U.S. and Canada border are more likely from local matured Bakken source rocks; c) subtle structural components enhancing the convergence of dispersed hydrocarbons over a large area; d) top seal and lateral barrier improving preservation, thus favouring oil productivity; e) orientation of maximum horizontal stress coincident with the direction of the variogram spatial continuity in ultimate recoverable reserves, so the direction of horizontal well has a significant impact on the oil productivity.

准噶尔盆地东部隆起煤层气成藏条件与选区评价

准噶尔盆地东部隆起具有较好的煤层气勘探前景,开展煤层气选区与评价,将为该区煤层气勘探提供科学依据和勘探方向。利用探井钻测录试资料、岩心分析测试数据和地震资料,开展井—震标定和地震剖面解释,编制了侏罗系八道湾组和西山窑组煤层连井剖面和煤层厚度分布图;分析了研究区内煤层气气源、煤岩基本特征、储层物性、含气性和保存条件等成藏主控因素。研究表明:(1)西山窑组煤层在沙奇凸起以北五彩湾凹陷—梧桐窝子凹陷连片分布,在沙奇凸起以南则主要分布于吉木萨尔凹陷—吉南凹陷;八道湾组煤层分割性较强,主要分布于凹陷内部分地区。(2)区内存在自源型煤层生物成因气、低成熟热成因气和深部外源型高成熟气条件。(3)煤岩有机组分以惰质组为主,镜质组次之,壳质组少量;煤岩镜质组反射率低(0.39%~0.47%),为低煤级煤;煤岩瓦斯气体成分主要为N_(2)、CO_(2)和CH_(4),其中N_(2)占绝对优势;煤岩总含气量中可燃气体(CH_(4))含量低。(4)煤层气富集成藏模式分为山前断陷富集成藏模式、深部凹陷富集成藏模式和开放斜坡逸散模式。(5)建立了煤层气评价参数和划分标准,五彩湾凹陷、梧桐窝子凹陷、吉木萨尔凹陷和吉南凹陷为煤层气勘探有利区;沙帐断褶带和石钱滩凹陷为较有利区;石树沟凹陷和古城凹陷为不利区。

Controlling Factors and Accumulation Model of Hydrocarbon Reservoirs in the Upper Cretaceous Yogou Formation, Koulele Area, Termit Basin, Niger

Based on the sedimentary and tectonic background of the Termit Basin, this paper focuses on the Upper Cretaceous Yogou Formation and uses organic geochemistry, logging, oil testing and seismic data to analyze the primary control factors of the hydrocarbon accumulation and establish corresponding model in order to predict favorable exploration target zones of hydrocarbon reservoirs. This study demonstrates that the Upper Cretaceous Yogou Formation is a self-generation and self-accumulation type reservoir. The Yogou Formation hydrocarbon reservoirs in the Koulele area are controlled by four factors：（1） the source rock is controlled by a wide range of YS1-YS2 marine shale,（2） the sandstone reservoir is controlled by the YS3 underwater distributary channel and storm dunes,（3） migration of hydrocarbons is controlled by faults and the regional monocline structure, and（4） the accumulation of hydrocarbons is controlled by lateral seal. The structures in the western Koulele area are primarily reverse fault-blocks with large throws, and the structures in the east are dominantly fault-blocks with small throws（co-rotating and reverse） and a fault-nose. In the western Koulele area, where the facies are dominated by storm dunes on a larger scale, it is easier to form lithologic reservoirs of sandstone lens. In the eastern Koulele area, high-quality channel sandstone reservoirs, fault-blocks with small throws, and the monocline structure benefit for the formation of updip pinch out lithologic traps, fault lithologic reservoirs and fault-nose structural reservoirs. Future exploration targets should be focused in the western storm dunes zone and eastern distributary channel sand zone with small fault-blocks.

Characteristics and controlling factors of shale gas reservoir in the Fuling area,Sichuan Basin

Statistical analysis of massive laboratory analytical data shows that for intervals in the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation in the Fuling area,Sichuan Basin,the total organic carbon content is 0.55%-5.89%with an average of 2.54%,presenting a gradual increase trend from top to bottom.Based on whole-rock X-ray diffraction data,the content of clay minerals of the shale is 16.6%-62.8%with an average of 40.9%,gradually decreasing from top to bottom.The content of brittle minerals gradually increases from top to bottom,ranging from 37.2%to 83.4%with an average of 59.1%.Porosity is 1.17%-7.98%with an average of 4.61%through the helium injection method.The horizontal permeability is 0.002-335.209 mD with an average of 23.785 mD by the steady-state method.Massive analytical data from the high-pressure mercury injection method show the micropores are well developed in the shale,and mainly provide the primary specific surface area of pores,while the micropores,transitional pores and mesopores primarily contribute to permeability.The pore types were observed using SEM in combination with argon ion polishing technology.From top to bottom of the shale interval,the organic pores increase and the inorganic pores decrease.Gas desorption data show that the total gas content is 0.44-5.19 m^(3)/t with an average of 1.97 m^(3)/t,and gradually increase from top to bottom of the shale interval.The development of marine shale gas reservoir in Well A is controlled by mineral compositions,the development characteristics of organic matter.TOC is not only a major intrinsic factor controlling the lower reservoir interval,but also an important material to provide the reservoir space for the shale gas.In the late diagenetic stage,the clay mineral assemblages changed from montmorillonite to illite,forming new micropores and leading to an increase of the porosity and great influences on the upper reservoir interval.The content of brittle minerals is more than 50%,facilitating formation of fractures,and the permeability performance can be enhanced significantly.In general,the Wufeng Formation and the bottom interval of the Longmaxi Formation are both high-quality reservoirs and primary pay intervals.

四川盆地蓬莱地区灯影组四段超深层白云岩储集层特征及主控因素

作为四川盆地超深层油气资源的主力产层之一,灯影组超深层碳酸盐岩储集层发育特征及其控制因素亟待进一步厘清。选取四川盆地内最新勘探突破的蓬莱地区灯影组灯四段超深层白云岩为主要研究对象,在野外露头、钻井岩心、显微薄片、阴极发光、扫描电镜及物性测试数据等资料的基础上,开展了储集层特征及主控因素等方面的研究。结果表明:(1)蓬莱地区灯四段储集岩主要包括凝块石白云岩、叠层石白云岩、泡沫绵层白云岩和砂屑白云岩;储集空间主要包括砂屑白云岩的晶间孔、晶间溶孔和溶洞,凝块石白云岩、叠层石白云岩和泡沫绵层白云岩的原生格架孔洞和后期溶蚀作用形成的溶蚀孔缝等。(2)凝块石白云岩和叠层石白云岩多发育孔洞缝型和孔洞型储集层,均具有较好的物性,孔隙度能达到4%以上,但前者平均渗透率可达2.43×10^(-3)μm^(2),后者仅为0.35×10^(-3)μm^(2)。(3)综合分析成岩演化史,认为灯四段储集层先后经历了沉积—准同生阶段、表生阶段、浅—中埋藏阶段和深层—超深层埋藏阶段的成岩改造。(4)蓬莱地区灯四段储集层发育具有自台地内部向台地边缘逐渐减弱的分布规律,总体上显示“相—断裂—溶蚀”三元综合成储模式。本研究明确了四川盆地蓬莱地区超深层白云岩储集层的特征及主控因素,可为后续超深层油气资源勘探开发提供理论基础。

Modeling the effects of constructed wetland on nonpoint source pollution control and reservoir water quality improvement

This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improvement at a catchment scale. The experimental field-scale wetland systems （four sets, 0.88 ha each） have been in operation since 2002, where water depth was maintained at 30-50 cm and hydraulic loading rate was at 6.3-18.8 cm/day. The wetland system was found to be adequate for treating polluted stream water with stable removal efficiency even during the winter. The integrated modeling system （modified-BASINS） was applied to the Seokmoon estuarine reservoir watershed and calibrated with monitoring data from constructed wetland, stream, and reservoir. The calibrated integrated modeling system estimated that constructing wetlands on 0.5% （about 114 ha） of the watershed area at the mouth of reservoir could reduce 11.61% and 13.49% of total external nitrogen and phosphorus loads, respectively. It also might improve the nitrogen and phosphorus concentration of the reservoir by 9.69% and 16.48%, respectively. The study suggested that about 0.1%-1.0% of the watershed area should be allocated for constructed wetland to meet specified water-quality standards for the estuarine reservoir at the polder area where land use planning is relatively less complicated.

“Exploring petroleum inside source kitchen”: Connotation and prospects of source rock oil and gas

Based on the transitional background of the global energy structure, exploration and development of unconventional oil and gas, and investigation of key basins, the unconventional oil and gas resources are divided into three types: source rock oil and gas, tight oil and gas, and retention and accumulated oil and gas. Source rock oil and gas resources are the global strategic supplies of oil and gas, the key resource components in the second 150-year life cycle of the future petroleum industry, and the primary targets for "exploring petroleum inside source kitchen". The geological connotation of source rock oil and gas was proposed, and the models of source rock oil and gas generation, expulsion and accumulation were built, and five source rock oil and gas generation sections were identified, which may determine the actual resource potential under available technical conditions. The formation mechanism of the "sweet sections" was investigated, that is, shale oil is mainly accumulated in the shale section that is close to the oil generation section and has higher porosity and permeability, while the "sweet sections" of coal-bed methane(CBM) and shale gas have self-contained source and reservoir and they are absorbed in coal seams or retained in the organic-rich black shale section, so evaluation and selection of good "sweet areas(sections)" is the key to "exploring petroleum inside source kitchen". Source rock oil and gas resources have a great potential and will experience a substantial growth for over ten world-class large "coexistence basins" of conventional-unconventional oil and gas in the future following North America, and also will be the primary contributor to oil stable development and the growth point of natural gas production in China, with expected contribution of 15% and 30% to oil and gas, respectively, in 2030. Challenges in source rock oil and gas development should be paid more attention to, theoretical innovation is strongly recommended, and a development pilot zone can be established to strengthen technology and promote national support. The source rock oil and gas geology is the latest progress of the "source control theory" at the stage of unconventional oil and gas. It will provide a new theoretical basis for the new journey of the upstream business in the post-industry age.

Reservoir Characteristics and Controlling Factors of Silurian Lower Kepingtage Formation in Tahe Area, Tarim Basin, NW China

With the breakthrough of exploration in Well TP16-1, the lower Kepingtage Formation becomes a key target for petroleum exploration of deep clastic reservoir in Tahe area. In this paper we focused on the research of the reservoir characteristics and its controlling factors in two sub-member formations（S1k11 and S1k13）. Based on X-ray diffraction, conventional physical properties data（porosity and permeability） and reservoir storage space data（casting thin section and scanning electron microscope）, we determined that the S1k1 Formation belongs to extra-low porosity and permeability reservoir, although the upper S1k13 Formation shows relative better physical characteristic than the lower S1k11 Formation. The development of storage space in the study area is controlled by sedimentary microfacies, diagenesis process. Reservoirs in S1k1 Formation are mainly located in channel（S1k11 sandstones） and sand flat（S1k13 sandstones）. The sand flat sediments with a more coarse grain size compared with the channel. In diagenesis, compaction is the major controlling factor for reducing the porosity, followed by cementation. Dissolution of diagenesis is the major controlling factor in enhancing the reservoir porosities. Compared with channel（S1k11） sandstones, sand flat sandstones（S1k13） have better reservoir quality for its weaker compaction, cementation and stronger dissolution. On the basis of sedimentary characteristics（grain size and subfacies）, physical property（porosity and permeability） and reservoir storage space, we divide the S1k1 reservoir into three categories（I, II and III）. Type I reservoir is high quality reservoir. It is mainly distributed in the south area of S1k11 and S1k13 reservoir. Type II is moderate reservoir. It is located in the middle of S1k11 reservoir and in the north of S1k13 reservoir. Type III is the poor reservoir. It is only located in the north of S1k11 reservoir.

塔里木盆地顺北地区顺北84X井超千米含油气重大发现及其意义

塔里木盆地顺北中部北东向走滑断裂带长期处于油气运聚富集的优势区,顺北8号走滑断裂带实钻揭示沿断裂带发育断控缝洞型油气藏,顺北84X井纵向上沿断裂带含油气高度高达1088 m,揭示断控缝洞型油气藏含油气高度大、不受现今构造高低控制。为查明断控缝洞型油气藏含油气高度的主控因素,立足顺北中部奥陶系碳酸盐岩油气藏的成藏地质条件和钻探成果,开展顺北84X井的储层、圈闭及成藏特征等石油地质条件分析,为深化断控缝洞型油气藏认识和向深层评价拓展提供支撑。研究表明:①走滑构造破碎是致密碳酸盐岩成储的关键,其储层发育深度不受碳酸盐岩地层埋深的控制,在近9000 m的埋深条件下仍发育断控缝洞型储集体;②上覆巨厚泥岩盖层顶封、两侧致密灰岩侧封、走滑断裂平面分段和纵向分层变形是形成断控缝洞型圈闭的关键;③油-源对比分析表明油气来自寒武系玉尔吐斯组烃源岩,证实了前期顺北中、东部“寒武多期供烃、构造破裂成储、原地垂向输导、晚期成藏为主、走滑断裂控富”的成藏模式的合理性。顺北84X井的发现揭示塔里木盆地超深层致密碳酸盐岩发育受走滑断裂控制,储层纵向深度大,油气充注足,超深层勘探潜力巨大。

多期构造应力控制走滑断控储层发育机理与差异性研究——以塔里木盆地顺北地区为例

塔里木盆地顺北油气田发育典型走滑断控缝洞型储层。区别于受原始沉积相带控制的基质孔洞、受岩溶改造的洞穴等储集类型,走滑断控缝洞型储层的形成主要受断裂活动期构造应力导致的破裂作用控制。为研究走滑断裂多期活动背景下构造应力控制的断控储层发育机理与分布规律,综合应用野外、岩心、测录井、地震及钻井动态等资料,开展不同走滑断裂、同一走滑断裂沿走向不同部位、垂向不同层系断控储层发育特征表征,并结合应力场数值模拟手段开展多期构造应力恢复,预测断控储层发育的主要时期与分布规律。结果表明,走滑断裂活动期不同分段内部应力状态差异显著,其中拉分段内部以张应力为主,主要派生张性裂缝;压隆段内部以挤压应力为主,派生裂缝类型多样。顺北地区勘探目的层奥陶系一间房组顶面断控裂缝主要在加里东中期Ⅲ幕及加里东晚期—海西早期发育,海西中—晚期及之后裂缝基本不发育,且滑移距大的顺北18号断裂带较顺北1号断裂带派生裂缝开度、密度更高。走滑断控储层具有“簇状”结构特征,断裂活动期不同分段内部应力状态控制储层结构差异,拉分段“空腔”多,以“双簇”结构为主,核带规模大,压隆段核带结构多,以“多簇”结构为主,分割性强;走滑断裂活动期应力强度控制储集空间类型与规模,小型断裂储集空间以裂缝为主,大型断裂带发育核带结构,断控储层规模与断裂活动强度呈正相关关系;断控裂缝发育主要受断裂早期活动控制,晚期由于地层埋深增大,岩石不易破裂,新派生裂缝发育较少。

柴达木盆地干柴沟地区古近系下干柴沟组上段页岩层系优势岩相及其控储因素

柴达木盆地干柴沟地区页岩油勘探近年获得重要突破,研究高原咸化湖盆岩相与储层特征对甜点识别具有重要意义。通过岩心和薄片观察、全岩矿物组成和原位微量元素分布测试、大面积视域扫描拼接成像、高压压汞与氮气吸附实验以及一维核磁共振分析,判识了岩相类型,系统研究了页岩储集性和含油性差异,提出了优势岩相和控储主因。研究结果表明:研究区储层有块状灰云岩(碳酸盐矿物含量>70%)、层状灰云岩(碳酸盐矿物含量50%~70%)、纹层状混积岩(碳酸盐矿物含量10%~50%)和断续状水平层理混积岩(碳酸盐矿物含量10%~50%)4种岩相。块状灰云岩和层状灰云岩孔隙以晶间孔为主,储集空间大且连通性好,孔隙中含油指数高,为优势岩相;纹层状混积岩基质孔隙发育较差,纹层密集发育的混积岩渗透性较好;断续状水平层理混积岩孔、缝不发育,储集性较差。优势岩相成储过程受3方面因素控制:①碳酸盐矿物组构决定宏孔发育程度;②陆源长英质细粒沉积物和黏土矿物含量控制比表面吸附性;③纹层发育程度最终改善储层渗透性能。

川中龙女寺地区中二叠统茅口组储层特征及其主控因素

近年来,川中龙女寺地区JT1井和MX145井等多口钻井在中二叠统茅口组获得高产工业气流,展现出茅口组良好的勘探开发潜力,但由于储层特征及其发育主控因素不清楚,严重制约了龙女寺地区茅口组进一步的油气勘探。以川中龙女寺地区茅口组储层为对象,开展储层岩性、物性和孔喉结构等地质特征及地球化学特征研究,提出了川中龙女寺地区中二叠统茅口组优质储层主控因素。研究结果表明:(1)龙女寺地区茅口组储层岩性为白云岩及灰岩2类,晶粒白云岩、角砾白云岩和颗粒灰岩为主要储层岩石类型。白云岩储层可划分为3大类、6个亚类,灰岩储层可划分为4大类、5个亚类。(2)晶间孔、非选择性溶孔和溶洞为茅口组储层主要储集空间类型,裂缝-孔洞型储层的构造-溶蚀缝、洞体系储集空间大,分布广泛且连通性好,为有利储层。(3)茅口组储层具有“沉积作用-白云石化作用构建骨架,岩溶作用-构造作用叠加改造”的形成与发育模式。沉积作用、白云石化作用和构造作用是优质储层的主要控制因素,角砾白云岩为优质储集岩。

川中蓬莱气区龙王庙组储层特征及其与磨溪—高石梯地区对比

川中蓬莱气区下寒武统龙王庙组钻遇良好碳酸盐岩储层,天然气显示好,成为继川中地区安岳大气田后龙王庙组重点勘探区之一,但储层发育规律不明制约了勘探部署。基于最新的钻井及分析测试等资料,系统分析了蓬莱气区龙王庙组储层特征及主控因素。研究认为,蓬莱气区龙王庙组具有陆源碎屑与碳酸盐混合沉积背景,储层主要分布在龙王庙组中上部;储集岩石类型主要为(残余)颗粒白云岩和结晶白云岩;储集空间类型主要为粒间溶孔、粒内溶孔、晶间溶孔及微裂缝;以低孔低渗储层为主,储层厚度主要介于10~42 m之间。储层发育受控于层序地层、岩性及成岩作用等,进积型准层序组和准层序中上部的(残余)颗粒白云岩和结晶白云岩是储层发育主要部位,大气淡水溶蚀、油气溶蚀作用及破裂作用是核心建设性成岩作用。对比安岳大气田主体区磨溪—高石梯地区,认为储层主控因素相近,主要受颗粒白云岩、溶蚀作用、破裂作用等控制,但蓬莱气区龙王庙组储层具有灰质含量高、陆源碎屑含量多、准同生期暴露弱等特点,寻找准同生期暴露的高能颗粒白云岩和细晶白云岩及表生岩溶改造的白云岩是蓬莱气区重点关注的储层目标。

面向多区域防洪的珠江流域水库群协同调度模型研究

珠江流域洪水组成与遭遇复杂多变,防洪保护对象多而分散,且兼顾供水、生态、发电、航运、库区安全等多种任务,水库群防洪调度面临多区域、多目标协同调度技术难题。以位于西江、北江、东江上的水库为研究对象,基于流域防洪格局和防洪任务阐明了水库群多区域协同防洪的调度节点和角色定位,提出了嵌套式多维属性的模型功能结构,构建了珠江流域水库群多区域协同防洪调度模型。以流域防洪极为不利的2005年6月中下游型大洪水为例进行流域水库群防洪调度模型研究,结果表明,通过龙滩水库加大拦蓄,岩滩水库、百色水库、西津水库、飞来峡水库等西江、北江水库群协同调度,可将西江梧州站洪峰流量削减至安全泄量50 400 m^(3)/s以下,较原设计调度方案多削减3 200 m^(3)/s,将三角洲思贤滘(马口+三水)断面洪峰削减至62 700 m^(3)/s,较原设计调度方案多削减4 500 m^(3)/s,有效保障了粤港澳大湾区城市的防洪安全。

碳酸盐岩储层高精度构造应力场模拟与裂缝多参数分布预测方法及其应用

构造裂缝是碳酸盐岩的主要储集空间之一,局部应力导致的构造破裂是影响裂缝发育的重要因素。基于有限元方法的构造应力场模拟已成为构造裂缝预测的重要方法,但尚未能解决模型设置与实际地质情况相差较大、最优边界条件获取效率低以及构造裂缝发育的主控因素不清晰等问题。①引入非均质岩石力学模型构建方法和自适应边界条件约束算法以提升应力场模拟的精度,根据储层破裂率和断裂活动性等参数定量表征储层裂缝发育特征;②定量探讨走滑断裂变形特征的差异和应力扰动对构造裂缝发育的影响,优选控制构造裂缝发育的最强因素构建碳酸盐岩裂缝型储集体发育指数并定量研究其主控因素;③以储集体发育规模预测为基础,结合单井裂缝测井和岩心解释成果,建立不同级别碳酸盐岩裂缝型储集体的地质模式。将该方法在中国塔里木盆地顺北地区18号断裂带及邻区奥陶系碳酸盐岩储层中应用。结果表明,张扭段、平移段与压扭段的裂缝发育程度依次降低。地层变形幅度越大,裂缝发育程度越高。储层岩石力学参数、距断裂的距离、水平两向应力差、应力非均质性系数和综合破裂率被用于构建裂缝型储集体发育指数,其分级结果与实际地质情况匹配度较高。