沉积学报
沉積學報
침적학보
ACTA SEDIMENTOLOGICA SINICA
2001年
2期
233-238
,共6页
唐洪明%曾凡刚%陈忠%赵敬松%沈明道%唐清山%柴利文%魏桂萍
唐洪明%曾凡剛%陳忠%趙敬鬆%瀋明道%唐清山%柴利文%魏桂萍
당홍명%증범강%진충%조경송%침명도%당청산%시리문%위계평
莲花油层%粘土矿物%蒸汽驱%沉积相%储层
蓮花油層%粘土礦物%蒸汽驅%沉積相%儲層
연화유층%점토광물%증기구%침적상%저층
辽河高升油田莲花油层富含稠油,搞清储层中粘土矿物的类型、含量、平面和纵向分布规律对整个稠油油藏开发方案的设计、油层保护、提高采收率等开发措施实施和稠油油藏形成条件等研究都具有极其重要的意义。本文利用X-衍射、电镜、热反应实验对高升油田莲花油层中的粘土矿物进行了系统研究。研究表明,莲花油层中的粘土矿物以蒙脱石为主,粘土矿物类型、含量分布主要受岩石类型和沉积相控制,含油饱和度大小对粘土矿物类型影响不大。蒸汽驱采油会导致储层中蒙脱石的含量减少,增加储层的微观非均质性。
遼河高升油田蓮花油層富含稠油,搞清儲層中粘土礦物的類型、含量、平麵和縱嚮分佈規律對整箇稠油油藏開髮方案的設計、油層保護、提高採收率等開髮措施實施和稠油油藏形成條件等研究都具有極其重要的意義。本文利用X-衍射、電鏡、熱反應實驗對高升油田蓮花油層中的粘土礦物進行瞭繫統研究。研究錶明,蓮花油層中的粘土礦物以矇脫石為主,粘土礦物類型、含量分佈主要受巖石類型和沉積相控製,含油飽和度大小對粘土礦物類型影響不大。蒸汽驅採油會導緻儲層中矇脫石的含量減少,增加儲層的微觀非均質性。
료하고승유전연화유층부함주유,고청저층중점토광물적류형、함량、평면화종향분포규률대정개주유유장개발방안적설계、유층보호、제고채수솔등개발조시실시화주유유장형성조건등연구도구유겁기중요적의의。본문이용X-연사、전경、열반응실험대고승유전연화유층중적점토광물진행료계통연구。연구표명,연화유층중적점토광물이몽탈석위주,점토광물류형、함량분포주요수암석류형화침적상공제,함유포화도대소대점토광물류형영향불대。증기구채유회도치저층중몽탈석적함량감소,증가저층적미관비균질성。
The Lianhua reservoir of Shahejie group(geology period E1) in Gaosheng Oil field , located in Liaohe granen faulting basin, is rich in heavy crude oil, with the burial depth being 1 450~1 700 m.The reservoirs have been under development for 22 years. The company has made great profit from the reservoir development by means of steam-flooding technology, but some problems have been found in the reservo i r with the technology application, because the difficulty in reservoir developme nt is increasing with the frequency of applying the technology. By the end of 19 98 the average steam flooding for every well has been four times, but the more s team-flooding, the less satisfactory the efforts to increase the production.
Therefore, a more comprehensive study of the types, content, and the horizonta l and vertical distribution characteristics of the clay minerals in the reservoi r is of most important consequence to the design of the heavy crude oil developme nt, reservoir protection, reservoir evaluation, and enhanced oil recovery (EOR) etc. The clay minerals in Lianhua reservoir are systematically studied by means of X-ray diffraction, scan electronic microscope and heat simulation experiment s.
The Lianhua reservoir is a sediment by gravity flow, with the rock types bein g gravel, sandstone, and mudstone, and the sedimentary depth being 50~600 m. L ian hua reservoir has excellent physical property, with the porosity being 20%~26% and the permeability being 1~4 μm2.
The studies show that the major clay minerals in Lianhua reservoir are montmoril lonite(60%~85%), illite (8%~20%), kaolinite (5%~25%), and chlorite (<5%). T he montm orillonite content decreases with the increase of the burial depth, but the kaol inite and illite content are just the opposite, because the porosity fluid in sa ndstone and gravels more easily circulative than that in mudstone, and the mont morillonite in sandstone can more easily convert into other clays.
For the study of the relationship between oil saturation and clay types, the rock is divided into two groups according to the oil saturation degree: the oil -saturated and non-saturated. The statistical result shows that the clay mi nera ls content and clay types have nothing to do with the oil saturation percentage.
The types, contents and distributions of clay minerals are mainly controlled by rock types and sedimentary facies. In general, the absolute content of the mo ntmorillonite increases with decrease of the sedimentary rock grains. The montmo rillonite in gravel and sandstone has a relatively lower content than that in mu dston e, but there is no much difference between the gravel and sandstone in their co ntents of montmorillonite. The relative content of montmorillonite in gravel and sandstone is 53.88%~85.99%, with an average of 67.94%, while the content in mu d stone is 69.54%~86.59%, with an average of 79.02%. The relative contents of kao li nite distribution decrease in the sequence of gravel, sandstone, and mudstone. But that of the illite is just the opposite. Lianhua reservoir is a turbidity cu rrent deposit in lake facies. Sandstone and gravel are mainly distributed in gro ove and branch groove facies, mudstone and aleurolite in deep lake , groove fron t margin and interlayer branch groove facies. During the evolving process of the facies from the main groove to branch groove, to the groove front margin, to th e interlayer branch groove, and finally to deep lake, the absolute content of cl ay minerals and the relative content of montmorillonite in Lianhua reservoir inc reases with the decline of the primary hydraulics.
By heat simulation experiments and a comparative study of the distribution c haracteristics of clay minerals before and after the steam flooding , it is foun d that the montmorillonite in the reservoir can increase because of kaolinite 's reaction to carbonate grains. But because the heavy crude oil carries the montm orillonite grains out, there finally is an approximately 1% deduction of the abs olute amount of montmorillonite in the reservoir after steam flooding. Because t he steam flooding can destroy the clay microstructure to a large degree, some cl ay minerals disperse and migrate to increase the micro-heterogeneity parameters of reservoir. According to the types, contents and distributions of the sensitiv e minerals, the main mechanism of formation damage during steam flooding is part icle migration and swelling of montmorillonite .Steam has a strong effect to the microstructure of the clay minerals.