Mechanistic investigation of gas injection treatment in a continental shale gas condensate reservoir

Low thermal evolution degree of gas and connected fracture network are key features in the continental shale gas reservoirs.When the pressure decreases lower than the dew point pressure,gas condensate diminishes the mobility of subsurface fluid forms in the near well region,which further reduces the productivity and final recovery factor in addition to the low connected fracture network.This work is motivated to investigate the application of gas injection,proven to be a feasible technique in conventional/marine-shale gas condensate reservoirs,in continental shale gas condensate reservoirs.We apply a compositional model to investigate the mechanism of gas injection treatment taking a continental shale gas condensate reservoir in the Fuxing area,Sichuan Basin,China as an example.The results demonstrate that for the removal of gas condensate during CO_(2)injection,re-vaporization plays the main mechanism through two processes including pressurization and development of miscibility,while the former is overwhelming.Considering the variation trend of the total volume of gas condensate,we divide the whole injection process into four and six stages in the single fracture model and fracture network model,respectively,and reason the trend with respect to phase behavior and flow pattern.A sensitive study on the injected gas type indicates that the sorting of the gas injection performance to remove gas condensate produced gas followed by CH4,and followed by CO_(2).Finally,we investigate the performance of cyclic produced-gas injection and optimize the injection scheme.This work provides technical and theoretical support for the development of continental shale gas reservoirs.

Migration and accumulation mechanisms and main controlling factors of tight oil enrichment in a continental lake basin

Based on the typical dissection of various onshore tight oil fields in China,the tight oil migration and accumulation mechanism and enrichment-controlling factors in continental lake basins are analyzed through nuclear magnetic resonance(NMR)displacement physical simulation and Lattice Boltzmann numerical simulation by using the samples of source rock,reservoir rock and crude oil.In continental lake basins,the dynamic forces driving hydrocarbon generation and expulsion of high-quality source rocks are the foundational power that determines the charging efficiency and accumulation effect of tight oil,the oil migration resistance is a key element that influences the charging efficiency and accumulation effect of tight oil,and the coupling of charging force with pore-throat resistance in tight reservoir controls the tight oil accumulation and sweet spot enrichment.The degree of tight oil enrichment in continental lake basins is controlled by four factors:source rock,reservoir pore-throat size,anisotropy of reservoir structure,and fractures.The high-quality source rocks control the near-source distribution of tight oil,reservoir physical properties and pore-throat size are positively correlated with the degree of tight oil enrichment,the anisotropy of reservoir structure reveals that the parallel migration rate is the highest,and intralayer fractures can improve the migration and accumulation efficiency and the oil saturation.

Geological conditions and reservoir characteristics of various shales in major shalehosted regions of China

China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major controlling factors.This study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale gas.In general,shales in China’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas generation.Marine strata generally show high degrees of thermal evolution.In contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these shales.The shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of shales.These shales are followed by those in the Niutitang and Longtan formations.In contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low porosities.Furthermore,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral contents.Despite a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some extent.For marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production.

Classification and Denominationof Flow Units for Clastic Reservoirsof Continental Deposit

On the basis of other researchers' achievements and the authors' understanding of flow units, a proposal on classification and denomination of flow units for clastic reservoirs of continental deposit is put forward according to the practical need of oilfield development and relevant theories. The specific implications of development and geology are given to each type of flow units, which has provided a scientific basis for oil development.

Thin-interbedded reservoirs prediction based on seismic sedimentology

Interference of thin-interbedded layers in seismic reflections has great negative impact on thin-interbedded reservoirs prediction.To deal with this,two novel methods are proposed that can predict the thin-interbedded reservoirs distribution through strata slices by suppressing the interference of adjacent layer with the help of seismic sedimentology.The plane distribution of single sand bodies in thin-interbedded reservoirs can be clarified.(1)The minimum interference frequency slicing method,uses the amplitude-frequency attribute estimated by wavelet transform to find a constant seismic frequency with the minimum influence on the stratal slice of target layer,and then an optimal slice corresponding the constant frequency mentioned above can be obtained.(2)The superimposed slicing method can calculate multiple interference coefficients of reservoir and adjacent layers of target geological body,and obtain superimposed slice by weighted stacking the multiple stratal slices of neighboring layers and target layer.The two proposed methods were used to predict the distribution of the target oil layers of 6 m thick in three sets of thin-interbedded reservoirs of Triassic Kelamayi Formation in the Fengnan area of Junggar Basin,Northwestern China.A comparison with drilling data and conventional stratal slices shows that the two methods can predict the distribution of single sand bodies in thin-interbedded reservoirs more accurately.

Geological theory and exploration & development practice of hydrocarbon accumulation inside continental source kitchens

Continental shale strata in China are rich in petroleum resources and are an important area to strengthen domestic oil exploration and development.Based on the latest progress in geological research and exploration and development of petroleum inside continental source kitchens of China National Petroleum Corporation exploration areas in recent two years,we have achieved the following results:(1)The geological connotations of continental hydrocarbon accumulation inside source kitchen and"sweet spot"have been proposed.The intra-source petroleum accumulation refers to the accumulation of liquid-rich hydrocarbons retained or captured in the continental organic-rich shale strata,and"sweet spot"refers to the favorable reservoir with higher oil content,better physical properties,easier to stimulate and higher in commercial development value in the overall oil-bearing continental source rock series,they can be divided into three types,interlayer,hybrid sediment and shale.(2)High-quality shale formations in both salt water and freshwater lacustrine basins can generate hydrocarbons on a large scale,shale strata have multiple types of favorable reservoirs with large-scale storage capacity,the intra-source shale strata are overall oil-bearing and large in resource scale,and there are multiple favorable shale series for development.The exploration and development practice is propelling the formation of a series of exploration and development key technologies with"sweet spot exploration"and"volume development"as the core.Some pilot tests of these technologies have provided an important scientific basis for the economic and effective development of hydrocarbon accumulation inside source kitchen,and popularization of these technologies have achieved encouraging results preliminarily.(3)Two types of continental intra-source petroleum resources in China have great potential,including medium-high maturity with liquid-rich hydrocarbons and medium-low maturity with organic-rich matter.The Ordos,Songliao,Bohai Bay and Junggar basins are the main areas of these resources.By addressing the theoretical and technical challenges in the exploration and development,the two types of resources inside continental source kitchens will become the realistic and major strategic replacement oil resources respectively in the future.

Accumulation and exploration of continental shale gas resources of Cretaceous Shahezi Formation in Lishu fault depression,Songliao Basin,NE China

Distribution characteristics,organic matter development characteristics,gas-bearing characteristics,reservoir characteristics,and preservation conditions of the Shahezi Formation shale of Lower Cretaceous in the Lishu fault depression,Songliao Basin,NE China,are analyzed using organic geochemical,whole rock,and SEM analysis data,and CO_(2)and N_(2) adsorption and high-pressure mercury injection experiment data in combination with the tectonic and sedimentation evolution of the region to reveal the geological conditions for enrichment and resource potential of continental shale gas.The organic-rich shale in the Lower Cretaceous of the Lishu fault depression is mainly developed in the lower submember of the second member of the Shahezi Formation(K_(1)sh_(2)^(1) Fm.)and is thick and stable in distribution.The shale has high TOC,mainly types II_(1) and II_(2) organic matter,and is in the mature to the over-mature stage.The volcanic activity,salinization,and reduction of the water environment are conducive to the formation of the organic-rich shale.The shale reservoirs have mainly clay mineral intergranular pores,organic matter pores,carbonate mineral dissolution pores,and foliated microfractures as storage space.The pores are in the mesopore range of 10–50 nm,and the microfractures are mostly 5–10μm wide.Massive argillaceous rocks of lowland and highstand domains are deposited above and below the gas-bearing shale separately in the lower submember of the K_(1)sh_(2)^(1) Fm.,act as the natural roof and floor in the process of shale gas accumulation and preservation,and control the shale gas enrichment.Based on the above understandings,the first shale gas exploration well in Shahezi Formation was drilled in the Lishu fault depression of Songliao Basin.After fracturing,the well tested a daily gas production of 7.6×10^(4) m^(3),marking a breakthrough in continental shale gas exploration in the Shahezi Formation(K1 sh Fm.)of the Lishu fault depression in Songliao Basin.The exploration practice has reference significance for the exploration of continental shale gas in the Lower Cretaceous of Songliao Basin and its periphery.

Practice and development suggestions of hydraulic fracturing technology in the Gulong shale oil reservoirs of Songliao Basin, NE China

This paper reviews the multiple rounds of upgrades of the hydraulic fracturing technology used in the Gulong shale oil reservoirs and gives suggestions about stimulation technology development in relation to the production performance of Gulong shale oil wells.Under the control of high-density bedding fractures,fracturing in the Gulong shale results in a complex fracture morphology,yet with highly suppressed fracture height and length.Hydraulic fracturing fails to generate artificial fractures with sufficient lengths and heights,which is a main restraint on the effective stimulation in the Gulong shale oil reservoirs.In this regard,the fracturing design shall follow the strategy of"controlling near-wellbore complex fractures and maximizing the extension of main fractures"Increasing the proportions of guar gum fracturing fluids,reducing perforation clusters within one fracturing stage,raising pump rates and appropriately exploiting stress interference are conducive to fracture propagation and lead to a considerably expanded stimulated reservoir volume(SRV).The upgraded main hydraulic fracturing technology is much more applicable to the Gulong shale oil reservoirs.It accelerates the oil production with a low flowback rate and lifts oil cut during the initial production of well groups,which both help to improve well production.It is suggested to optimize the hydraulic fracturing technology in six aspects,namely,suppressing propagation of near-wellbore microfractures,improving the pumping scheme of CO_(2),managing the perforating density,enhancing multi-proppant combination,reviewing well pattern/spacing,and discreetly applying fiber-assisted injection,so as to improve the SRv,the distal fracture complexity and the long-term fracture conductivity.

济阳页岩油开发“三元”储渗理论技术与实践

基于济阳坳陷页岩油储层上万米岩心资料与60余口水平井的开发实践,提出济阳页岩油“储元”、“缝元”、“压元”的“三元”储渗理论。“三元”协同支撑济阳页岩油的富集高产:“储元”控制页岩油的富集,咸化湖盆无机孔-缝及灰-泥优质纹层组构发育利于页岩油储集,高生烃能力、高游离烃含量为高产提供物质基础;“缝元”控制页岩油的渗流,天然裂缝为页岩油的运移和聚集提供渗流通道,压裂改造缝沟通天然裂缝形成复杂缝网,为高产提供渗流基础;“压元”控制页岩油的高产稳产,高地层压力为油气运聚提供原始动力,压裂增能可进一步提高岩石及流体弹性能,强化孔缝原油渗吸置换,减缓应力敏感性,为长期稳产提供能量基础。基于“三元”储渗理论,形成了以立体井网优化、立体均衡压裂、全周期优化调控为核心的立体开发技术,有效指导了现场生产实施,为济阳页岩油规模化效益开发提供技术支撑。

陆相湖盆水下喷发火山岩储层特征及发育模式——以松辽盆地长岭断陷查干花次凹为例

在松辽盆地长岭断陷陆相湖盆水下喷发的火石岭组火山碎屑岩中发现了工业油气,有广阔的勘探前景。研究针对火石岭组水下喷发火山碎屑岩储层的储集空间特征、物性特征及孔隙结构差异开展,分析不同类型储层物性差异原因及其形成和演化过程。主要有以下4个方面:①凝灰岩中火山玻璃含量较高,储集空间以脱玻化孔和溶蚀孔为主,并且粒度越粗物性越好,孔隙规模、孔径大小、孔隙丰度等方面逐渐变大;沉凝灰岩黏土矿物含量高,以黏土矿物晶间孔为主,物性差;凝灰质砂岩中长石、岩屑和浊沸石等易溶组分含量高,以溶蚀孔为主。②研究区火山碎屑岩储层原生孔隙不发育,储层较为致密,平均孔隙度为2.43%,渗透率平均值为0.076×10^(-3)μm^(2),粗粒凝灰岩孔隙度最高,其次是凝灰质砂岩和细粒凝灰岩,沉凝灰岩物性最差。③脱玻化作用是凝灰岩储层中高孔隙度和超低渗透率的重要原因,中成岩阶段的2次油气充注导致岩石发生有机酸溶蚀,此外,裂缝可以为有机酸和深部热液提供运移通道,导致后期溶蚀,并连接各种分散的溶蚀孔隙,提高储集空间的有效性。④近源相带气携水下火山碎屑流亚相粗粒凝灰岩储层是油气勘探的有利目标。

极端耗水层带形成机制及流场调控增效模式——以陆相砂岩特高含水后期整装油田为例

以胜利油区陆相砂岩油藏整装油田为代表,主力单元进入特高含水后期(含水率大于95%),局部区域出现极端耗水现象,水油比急剧上升,注入水利用率大幅下降,吨油操作成本成倍增加,经济效益变差,但油藏中还有60%左右剩余地质储量。注入水沿着极端耗水层带窜流是制约陆相砂岩整装油田特高含水后期效益开发的关键问题。以提高特高含水老油田开发效益为目标,明晰了极端耗水层带形成机制及调控机理,建立了基于老井的变流线调控极端耗水层带扩波及方法,形成特高含水后期油藏精准描述及调控极端耗水层带扩波及的效益开发技术体系。通过应用流场调控技术,使传统认为含水率98%近废弃油藏开展示范应用,基于极端耗水层带流场调控经济寿命期延长10a以上,产油量大幅增加,含水率下降,吨油操作成本下降,实现了特高含水后期老油田低成本开发。

基于沉积学原理的被动陆缘陆坡古地貌恢复方法

深入了解被动陆缘陆坡古地貌如何控制深水重力流储层的形成与分布对深水油气勘探意义重大。在少井探区,基于三维地震的地层厚度印模法在古地貌研究中应用广泛,但是,陆坡区容易因沉积物供给不足而处于“半饥饿欠补偿”状态和陆坡地形坡度的存在会影响该方法的适用性和准确性,对沉积体系和油气储层的分布特征分析产生不利影响。为此,根据沉积型陆坡的特点,对地层厚度印模法进行了两方面的补充与改进:其一,通过三维地震资料的分析明确目的层陆坡补偿状态,讨论了地层厚度印模法的适用性;其二,根据研究区陆坡演化过程,以沉积物体积等分方式求取目的层段各层序对应的潜在坡度趋势,基于此实现古陆坡地形坡度校正。利用改进后的方法对非洲西部尼日尔三角洲盆地下陆坡古地貌进行恢复的结果与研究区现有构造演化认识高度一致,符合“构造活动主导地貌特征”这一普遍认识。另外,地震属性刻画出的深水沉积体系分布特征与古地貌恢复结果间存在良好的耦合关系。应用实例证明了改进方法的科学性和研究区古地貌恢复结果的客观性。

Shale oil development techniques and application based on ternary-element storage and flow concept in Jiyang Depression,Bohai Bay Basin,East China

The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.

四川盆地自流井组页岩油气地质特征及富集规律

为研究中高成熟陆相页岩油气形成条件及富集规律,以四川盆地自流井组东岳庙段与大安寨段两套富有机质页岩为研究对象,采用岩石薄片、全岩X衍射、有机碳含量、岩石热解、干酪根碳同位素、氩离子抛光-扫描电镜、物性等多种实验测试技术方法,基于岩相、烃源、储集、保存及含油气性等研究,总结了中高成熟陆相页岩油气富集规律。研究结果表明:研究区陆相富有机质页岩岩相及组合类型多样,以富含方解石介壳纹层为特点;页岩物性明显好于介壳灰岩与粉砂岩夹层,其中以黏土质页岩与介壳灰质页岩宏观物性与微观孔隙(类型、结构)最佳;整体保存条件好,具有构造稳定、高压-超高压特征,油气同产。综合分析认为自流井组陆相富有机质页岩具有“两相控烃控储、压缝控富控产”的页岩油气富集规律。基于目前盆地重点探区及相邻层段的勘探实践,提出加强重点地区地质-开发-工程一体化技术攻关,加强非常规页岩油气-常规油气整体综合评价研究与勘探部署。

海陆过渡相与海相页岩气储层特征差异性分析——以南川地区龙潭组与龙马溪组为例

南川地区发育海陆过渡相、海相2种沉积类型的页岩层系,以龙马溪组为代表的海相页岩气实现了商业开发,而对以龙潭组为代表的海陆过渡相页岩气的认识程度较低。利用野外露头、钻井岩芯、薄片及氩离子抛光扫描电镜等实验数据和地层微电阻率扫描成像(FMI)测井等资料,从沉积相、岩性组合、储集条件、矿物组分、可压性及含气性等方面,开展这2套页岩储层特征的差异性分析。结果表明,2套储层在以上方面都存在较大差异:①龙潭组岩性复杂,发育粉砂质页岩、炭质页岩、灰质页岩、灰岩及煤层,而龙马溪组主要以硅质页岩为主;②受岩性、有机质类型及热演化程度影响,龙潭组储集空间主要以微裂缝(粒缘缝和收缩缝)和无机孔为主,而龙马溪组主要以有机质孔和微裂缝为主;③龙潭组页岩黏土矿物含量高(47.6%),脆性矿物含量低(35.8%),杨氏模量低(32.3 GPa),泊松比高(0.3),塑性较强,可压性差于龙马溪组页岩;④龙潭组页岩含气量平均为2.2 m^(3)/t,吸附气占比54.5%,而龙马溪组页岩含气量平均为5.2 m^(3)/t,吸附气占比43.3%。通过2套页岩层系储层差异性分析,明确了龙潭组页岩储层具有岩性复杂、黏土矿物含量高、可压性差、吸附气占比高的特征。龙潭组谭一段页岩连续厚度大、含气量高、储集物性好,从整体性评价来看,是龙潭组的“甜点”段;但其黏土矿物含量也高,且地质“甜点”与工程“甜点”的耦合性较龙马溪组页岩差,建议优化压裂工艺,提高缝网改造体积和单井产量,实现勘探突破。

陆相页岩油储层孔隙结构表征和渗流规律研究进展及展望

目前中国在陆相页岩油勘探开发过程中遇到了诸多难题和挑战。陆相页岩油储层孔隙结构复杂和渗流能力差极大地影响页岩油可动性,是制约陆相页岩油高效开发的突出问题。针对页岩开发面临的突出问题,简要介绍了国内外学者对页岩油储层孔隙结构表征和页岩油渗流规律研究方法和技术手段的现状、存在问题及今后的发展趋势。研究表明:多尺度、精细且连续表征是对陆相页岩油储层孔隙结构表征的关键;建立行业统一孔隙结构表征技术和分类评价标准是陆相页岩油有效开发的地质依据;多物理模型和实验手段相结合是陆相页岩油渗流表征的基础;加强数值模拟和物理模拟及室内实验结合是陆相页岩油渗流机理研究的主攻方向。这为突破陆相页岩油开发瓶颈提供了重要的指导思想,对实现陆相页岩油储层的高效开发具有重要意义。

陆相湖盆致密油充注运聚机理与富集主控因素

通过中国陆上不同类型致密油典型实例解剖,开展烃源岩、储集层、原油等样品测试分析,运用核磁-驱替物理模拟、格子玻尔兹曼数值模拟等技术方法,研究了中国陆相湖盆致密油充注运聚机理与富集主控因素。研究表明陆相湖盆致密油充注运聚机理:优质烃源岩生排烃动力是决定致密油充注效率和聚集效果的动力基础,原油运移阻力是影响致密油充注效率和聚集效果的关键要素,充注动力与致密储集层孔喉阻力耦合作用控制聚集效果及富集程度。陆相湖盆致密油富集程度主要受烃源岩、储集层孔喉大小、储集层结构各向异性及裂缝4大因素控制:优质烃源岩控制致密油近源分布,储集层物性及孔喉大小与致密油富集程度呈正相关,储集层结构各向异性揭示顺层运移速率最高,层内裂缝提高运聚效率与含油饱和度。

松辽盆地古龙页岩油储集层压裂改造工艺实践与发展建议

阐述了古龙页岩油多轮次压裂工艺技术迭代升级历程,结合古龙页岩油井开发生产动态,提出关于压裂改造工艺的发展建议。高密度页理缝控制下,古龙页岩压裂裂缝形态复杂,但缝高、缝长受到明显抑制,人工裂缝扩不高、延不远,成为古龙页岩油储集层有效改造的主要制约,压裂设计应遵循“控近扩远”设计理念。提升胍胶压裂液的比例、降低段内簇数、提高施工排量、正向利用应力干扰有利于裂缝扩展延伸,改造体积显著增大。主体压裂工艺迭代升级后的油藏适应性明显提升,实现了低返排率下的快速见油,井组生产初期含油率升高,有利于提高页岩油井产量。建议下一步围绕抑制近井微缝扩展、完善CO_(2)泵注程序、合理控制射孔密度、优化支撑剂组合模式、合理优化井网井距、谨慎使用纤维拌注工艺6个方面,进一步迭代优化压裂工艺技术,提升压裂改造体积、远井裂缝复杂程度以及长效导流能力。

鄂尔多斯盆地东缘海陆过渡相页岩岩相特征及储层差异

鄂尔多斯盆地东缘石炭系—二叠系发育海陆过渡相沉积岩系,其内也实现了煤层气和致密气等多种类型天然气的勘探突破和商业开发,是非常规天然气重要接替领域之一。为揭示海陆过渡相页岩岩相类型差异及分布规律,指导下一步油气勘探开发,基于野外露头、岩心以及全岩矿物,综合划分了石炭系本溪组、二叠系太原组和山西组页岩岩相类型,并结合含气性、力学性质、孔隙度和渗透率测试等资料,明确了不同岩相类型下对储层发育特征的控制作用。研究结果表明:①海陆过渡相页岩以黏土类、硅质类和混合类为主,其中潮坪相以纹层状低有机质—混合页岩为主,潟湖相以纹层状高有机质—富黏土硅质页岩为主,三角洲相以块状低有机质—富硅质黏土质页岩为主;②海陆过渡相页岩开发潜力较好,有机碳含量中等(平均约2.26%),低孔隙度(约1.41%)低渗透率(约0.12 mD),含气量偏低(约1.23 m^(3)/t),具有低泊松比(约0.2)和高弹性模量特征(约22 GPa);③含气性和物性综合分析优势岩相为高有机质—富硅质黏土质页岩、中有机质—富硅质黏土质页岩等,在潮坪相和潟湖相更为发育。结论认为,海陆过渡相沉积环境多变,岩相类型差异明显,应立足“优势环境—优势层段—优势岩相”的勘探开发思路,寻找地质和工程甜点叠合区段进行勘探部署,该认识可为海陆过渡相页岩气和煤系多层系天然气规模效益开发提供技术支撑,有助于实现非常规海陆过渡相页岩气科学开发。

济阳陆相断陷盆地页岩油富集高产规律

济阳坳陷具有丰富的页岩油资源,2019年以来,陆续有YYP1,FYP1,BYP5等多口井获得峰值日产油量超100t/d的高产工业油流,展现了良好的勘探开发前景,总结济阳页岩油地质特征,分析其富集高产规律,对于实现页岩油经济有效开发具有重要指导意义。在对济阳页岩油勘探开发实践回顾的基础上,通过对页岩油岩相特征、储集空间、含油性、可压性的系统分析,明确了济阳页岩油富集高产的主控因素。研究表明,济阳页岩油资源丰富但是分布零散,油藏埋藏深,温度及压力系数高,具有构造复杂、岩相复杂、地应力复杂、流体性质复杂等“四复杂”的特点。烃源岩厚度大、有机质含量高、热演化程度适中、咸化湖盆富碳酸盐岩相发育是页岩油富集的主要因素,无机孔-缝网络发育、地层压力系数高、脆性矿物含量高、可压性好,CO_(2)扩孔增能、多尺度缝网组合压裂是济阳页岩油高产的主要因素。济阳页岩油的突破,展现了陆相断陷盆地页岩油广阔的勘探开发前景,对中外同类型油藏具有较大的指导与借鉴意义。