石油与天然气地质
石油與天然氣地質
석유여천연기지질
OIL & GAS GEOLOGY
2014年
2期
286-294
,共9页
杨超%张金川%李婉君%荆铁亚%孙睿%王中鹏%何伟%卢亚亚
楊超%張金川%李婉君%荊鐵亞%孫睿%王中鵬%何偉%盧亞亞
양초%장금천%리완군%형철아%손예%왕중붕%하위%로아아
氩离子抛光-扫描电镜%孔隙特征%油气成藏%沙河街组%辽河坳陷
氬離子拋光-掃描電鏡%孔隙特徵%油氣成藏%沙河街組%遼河坳陷
아리자포광-소묘전경%공극특정%유기성장%사하가조%료하요함
FIB-SEM%pore characteristics%hydrocarbon accumulation%Shahejie Formation%Liaohe Depression
为深入研究辽河坳陷次级凹陷沙河街组三、四段泥页岩储层孔隙特征及成藏意义,选取了5口泥页岩钻井岩心样品进行了氩离子抛光-扫描电镜( FIB-SEM)、氦气吸脱附、X-衍射全岩分析、干酪根镜检及配套有机地化等实验,从微观孔隙结构到成藏意义进行了深入探讨。结果表明,研究层段共存在粒间孔、粒内孔、晶间孔、溶蚀孔、有机孔、微裂缝6种孔隙类型。孔隙发育不仅与沉积压实、胶结、溶解作用相关,另外还与页岩岩性、矿物组构、有机质类型、有机地化等因素密切相关。粘土矿物集合体粒间孔和层间微孔缝对页岩油气的赋存和运移贡献最大,且是页岩储层各向异性(渗透率)的主要控制因素;溶蚀孔及晶间孔次之;有机孔因相对不发育,对页岩油气的渗透贡献较小,但仍然是吸附态页岩油气的主要场所;微裂缝的影响不容忽视,是沟通宏孔与中孔的主要微通道。另外,低熟条件下粘附-结合态有机质中有机孔的大量发现表明粘土矿物对有机质的早期催化生烃起到重要作用,同时,有机质与矿物(主要是粘土矿物)紧密共生的保存特点,也反映了有机质保存形式与油气生成之间的密切关系。实验同时表明无定形体是研究层段生成页岩油气的主要贡献者。
為深入研究遼河坳陷次級凹陷沙河街組三、四段泥頁巖儲層孔隙特徵及成藏意義,選取瞭5口泥頁巖鑽井巖心樣品進行瞭氬離子拋光-掃描電鏡( FIB-SEM)、氦氣吸脫附、X-衍射全巖分析、榦酪根鏡檢及配套有機地化等實驗,從微觀孔隙結構到成藏意義進行瞭深入探討。結果錶明,研究層段共存在粒間孔、粒內孔、晶間孔、溶蝕孔、有機孔、微裂縫6種孔隙類型。孔隙髮育不僅與沉積壓實、膠結、溶解作用相關,另外還與頁巖巖性、礦物組構、有機質類型、有機地化等因素密切相關。粘土礦物集閤體粒間孔和層間微孔縫對頁巖油氣的賦存和運移貢獻最大,且是頁巖儲層各嚮異性(滲透率)的主要控製因素;溶蝕孔及晶間孔次之;有機孔因相對不髮育,對頁巖油氣的滲透貢獻較小,但仍然是吸附態頁巖油氣的主要場所;微裂縫的影響不容忽視,是溝通宏孔與中孔的主要微通道。另外,低熟條件下粘附-結閤態有機質中有機孔的大量髮現錶明粘土礦物對有機質的早期催化生烴起到重要作用,同時,有機質與礦物(主要是粘土礦物)緊密共生的保存特點,也反映瞭有機質保存形式與油氣生成之間的密切關繫。實驗同時錶明無定形體是研究層段生成頁巖油氣的主要貢獻者。
위심입연구료하요함차급요함사하가조삼、사단니혈암저층공극특정급성장의의,선취료5구니혈암찬정암심양품진행료아리자포광-소묘전경( FIB-SEM)、양기흡탈부、X-연사전암분석、간락근경검급배투유궤지화등실험,종미관공극결구도성장의의진행료심입탐토。결과표명,연구층단공존재립간공、립내공、정간공、용식공、유궤공、미렬봉6충공극류형。공극발육불부여침적압실、효결、용해작용상관,령외환여혈암암성、광물조구、유궤질류형、유궤지화등인소밀절상관。점토광물집합체립간공화층간미공봉대혈암유기적부존화운이공헌최대,차시혈암저층각향이성(삼투솔)적주요공제인소;용식공급정간공차지;유궤공인상대불발육,대혈암유기적삼투공헌교소,단잉연시흡부태혈암유기적주요장소;미렬봉적영향불용홀시,시구통굉공여중공적주요미통도。령외,저숙조건하점부-결합태유궤질중유궤공적대량발현표명점토광물대유궤질적조기최화생경기도중요작용,동시,유궤질여광물(주요시점토광물)긴밀공생적보존특점,야반영료유궤질보존형식여유기생성지간적밀절관계。실험동시표명무정형체시연구층단생성혈암유기적주요공헌자。
In order to further study the pore characteristics of shale reservoir oin Sha-3 and Sha-4(the 3rd and 4th Member of Shahejie Formation respectively ) and their accumulation significance in Liaohe depression ,samples from 5 wells were chosen to conduct a series of experiments including focused ion beam-scanning electron microscope(FIB-SEM),helium adsorption and desorption ,whole rock analysis by XRD ,microscopic examination of kerogen and related organic geochem-istry experiments.The results show that there are 6 types of pore including intergranular pore ,intragranular pore ,inter-crystal pore,dissolution pore,organic pore and micro-cracks.Furthermore,development of these pores are not only related to sedimentary compaction , cementation and dissolution , but also closely related to the lithology , mineral fabric , type of organic matter and organic geochemistry .The intergranular pores and interlayer micropores and cracks of clay mineral ag-gregates make the greatest contribution to the storage and migration of shale oil and gas ,and they are also the major con-trolling factor of the anisotropic ( permeability ) of the shale reservoir , followed by the dissolution pores and inter-crystal pores.The organic pores contribute the least due to the relatively poor development ,but they still plays an important role in storage of absorbed shale oil and gas .Meanwhile , micro-cracks are also negligible in connecting macro-pores and me-so-pores.In addition ,large amount of organic pores are found in adhesive-combining organic matter with low maturity ,in-dicating that clay minerals play an important role in the early period of hydrocarbon generation .The feature of close sym-biosis between organic matter and minerals ( mainly clay minerals ) also reflects the close relationship between the preser-vation pattern of organic matter and hydrocarbon generation .The experiments also demonstrate that the amorphous solid is the major contributor to the generation of shale oil and gas in Sha-3 and Sha-4 shale .