本文選題：長石 + 碳酸鹽礦物　； 參考：《中國石油大學(xué)(華東)》2015年博士論文

【摘要】：含油氣盆地碎屑巖儲層埋藏過程中成巖地質(zhì)流體及其控制下的礦物溶蝕、溶蝕物質(zhì)傳輸及次生礦物沉淀等物理化學(xué)作用過程,對儲層質(zhì)量具有重要的改造作用,屬于地質(zhì)學(xué)前沿研究。論文綜合利用沉積巖石學(xué)、實驗地球化學(xué)、模擬地球化學(xué)、石油地質(zhì)學(xué)等多學(xué)科交叉方法,系統(tǒng)總結(jié)了碎屑巖儲層中長石和碳酸鹽礦物的(選擇性)溶蝕現(xiàn)象和長石溶蝕次生產(chǎn)物的不均勻沉淀現(xiàn)象,厘定了東營凹陷勝坨地區(qū)沙三中亞段-沙四段碎屑巖儲層和南堡凹陷高柳地區(qū)沙三段碎屑巖儲層成巖事件及成巖流體演化過程;結(jié)合熱動力學(xué)約束的流體-巖石相互作用模擬實驗,提出了勝坨地區(qū)相對封閉體系中有機質(zhì)熱演化生成CO_2等酸性流體選擇性溶蝕長石(不溶蝕碳酸鹽礦物)形成規(guī)模性次生孔隙的機理,以及高柳地區(qū)相對開放體系中大量大氣淡水和有機質(zhì)熱演化生成CO_2等酸性流體共同溶蝕長石和碳酸鹽礦物形成規(guī)模性次生孔隙的機理。結(jié)合長石溶蝕-物質(zhì)傳輸-次生礦物沉淀數(shù)值模擬實驗約束下次生礦物(粘土礦物和石英膠結(jié)物)不均勻沉淀的數(shù)值模擬實驗和實際地質(zhì)體中長石溶蝕次生孔隙、次生礦物特征,明確了封閉成巖體系和開放成巖體系中礦物溶蝕作用的物性響應(yīng)和次生礦物的再分配模式。巖石學(xué)特征表明,碎屑巖儲層中可發(fā)育長石弱溶蝕-碳酸鹽礦物強沉淀組合(I)、長石強溶蝕-碳酸鹽礦物不(弱)溶蝕組合(Ⅱ)、長石強溶蝕-碳酸鹽礦物強溶蝕組合(Ⅲ)、長石弱溶蝕-碳酸鹽礦物強溶蝕組合(Ⅳ)等4種類型的長石和碳酸鹽礦物成巖組合關(guān)系,其中組合I和Ⅱ在勝坨地區(qū)普遍發(fā)育,組合III在高柳地區(qū)普遍發(fā)育。在碳酸鹽膠結(jié)作用相對較弱的儲層中可發(fā)育長石弱溶蝕-少量粘土礦物-少量石英膠結(jié)物組合(Ⅰ’)、長石弱溶蝕-大量粘土礦物-少量石英膠結(jié)物組合(Ⅱ’)、長石大量溶蝕-大量粘土礦物-大量石英膠結(jié)物組合(Ⅲ’)、長石大量溶蝕-大量粘土礦物-少量石英膠結(jié)物組合(Ⅳ’)、長石大量溶蝕-少量粘土礦物-少量石英膠結(jié)物組合(Ⅴ’)等5種類型的長石溶蝕-次生溶蝕產(chǎn)物成巖組合關(guān)系,其中組合Ⅰ’和Ⅲ’在勝坨地區(qū)發(fā)育,組合Ⅳ’在民豐地區(qū)發(fā)育,組合Ⅴ’在高柳地區(qū)發(fā)育,Ⅱ’可見于高柳地區(qū)小部分儲層。CO_2和CH_3COOH溶解長石和碳酸鹽礦物的化學(xué)平衡常數(shù)和熱動力學(xué)約束下的水-巖反應(yīng)數(shù)值模擬表明,在鉀長石-方解石-酸-H2O體系中,相同溫度條件下溶蝕鉀長石的化學(xué)反應(yīng)平衡常數(shù)大大高于溶解方解石的化學(xué)反應(yīng)平衡常數(shù),同一流體-巖石體系中溶解方解石比溶解鉀長石需要更低的pH,造成碳酸鹽礦物的溶解對流體規(guī)模和侵蝕性具有更強的依賴性,從而在地質(zhì)時間尺度流體-巖石相互作用過程中發(fā)育鉀長石溶蝕-方解石不溶蝕(甚至沉淀)的現(xiàn)象。酸濃度和水體積增大促進礦物溶解,離子鹽效應(yīng)促進礦物溶解,同離子效應(yīng)抑制礦物溶解,鉀長石溶蝕生成伊利石比生成高嶺石更能促進鉀長石的溶解。勝坨地區(qū)沙三中亞段-沙四段斷裂發(fā)育弱,流體超壓發(fā)育,自生礦物穩(wěn)定同位素和地層水化學(xué)特征表明,儲層成巖過程中大氣水影響弱,儲層具有典型的相對封閉成巖體系。在該體系中,早成巖階段泥巖中有機質(zhì)微生物發(fā)酵作用為早期碳酸鹽膠結(jié)物提供碳源,造成膠結(jié)物在互層的砂巖層邊部大量沉淀,形成長石弱溶蝕-碳酸鹽礦物強沉淀組合;中成巖階段,缺少大氣淡水供給,地層內(nèi)部水體有限,碳酸鹽礦物溶解被化學(xué)平衡抑制,有機質(zhì)熱脫酸生成大量CO_2和有機酸進入儲層并選擇性溶蝕長石礦物,形成規(guī)模性次生孔隙。高柳地區(qū)斷裂體系發(fā)育,流體超壓弱且發(fā)育局限,自生礦物穩(wěn)定同位素和地層水化學(xué)特征表明,儲層成巖過程中大氣淡水影響強烈,儲層具有典型的相對開放成巖體系。初始埋藏沉降階段,隨著地層溫度的升高,儲層中沉淀出較多碳酸鹽膠結(jié)物;構(gòu)造抬升階段和后續(xù)埋藏階段,斷裂體系強烈發(fā)育使得大量大氣淡水下滲到中深部儲層,同時在中成巖階段,有機質(zhì)熱脫酸作用貢獻一定量的酸性流體,在大規(guī)模水體存在的相對高溫條件下,儲層中長石和碳酸鹽礦物同時發(fā)生溶解作用,形成規(guī)模性次生孔隙。砂層中注入富CO_2酸性流體時,耦合長石溶解-物質(zhì)傳輸-次生礦物沉淀的數(shù)值模擬表明,從上游到下游,適當(dāng)條件下砂層中發(fā)育3個區(qū)帶:溶解帶—過渡帶—沉淀帶。溶解帶溶解長石,不沉淀次生礦物;過渡帶溶蝕長石,沉淀高嶺石;沉淀帶溶蝕長石,沉淀高嶺石和石英礦物。溫度增大、礦物反應(yīng)速率升高、注入水流速降低及離子濃度增大傾向于縮短溶解帶和過渡帶;溫度降低、礦物反應(yīng)速率降低、注入水流速增大及離子濃度降低擴展溶解帶和過渡帶。在斷裂體系不發(fā)育地層中,近地表低溫-高流速砂層傾向于形成礦物組合Ⅴ’,淺層砂層傾向于形成礦物組合Ⅳ’,中深層高溫-低流速砂層傾向于形成礦物組合Ⅲ’;斷裂的發(fā)育增加礦物組合Ⅳ’和Ⅴ’在中深層砂層發(fā)育的可能性。在勝坨地區(qū)中成巖階段相對封閉的高溫-低流速成巖體系中,碳酸鹽膠結(jié)物不(弱)溶解,同時長石顆粒溶蝕產(chǎn)物發(fā)生準(zhǔn)原地沉淀,長石溶蝕次生孔隙為調(diào)配型次生孔隙,溶蝕作用未能有效改善儲層物性。在高柳地區(qū)中成巖階段大氣淡水大量供給的高溫-高流速開放成巖體系中,長石和碳酸鹽礦物同時被強烈溶解,且長石溶蝕產(chǎn)物被有效帶出儲層,礦物溶蝕次生孔隙為增孔型次生孔隙,溶蝕作用有效改善物性。
[Abstract]:During the burial process of the clastic rock reservoir in the oil and gas basin, the physical and chemical processes, such as the rock geological fluid and its controlled mineral dissolution, the transport of the dissolved material and the secondary mineral precipitation, have an important transformation effect on the reservoir quality. It belongs to the study of the geological pre-school. The paper combines sedimentary petrology, experimental geochemistry, and simulated earth. Chemical, petroleum geology and other interdisciplinary methods have systematically summarized the phenomenon of (selective) dissolution of feldspar and carbonate minerals in the clastic reservoir and the uneven precipitation of the secondary production of feldspar, determined the debris reservoir of the S3 middle subsection Sha four section of the Shengtuo area of Dongying sag and the three fragment of Sha three section in the high willow area of Nanpu Sag. The formation of rock formation and the evolution process of diagenetic fluid, combined with the simulation experiments of fluid rock interaction with thermal dynamic constraints, proposed the mechanism of the formation of the secondary porosity of the acidic fluid selective corroded feldspar (not dissolved carbonate minerals) in the relative closed system of the Shengtuo region and the formation of CO_2 and other acidic fluids. The thermal evolution of a large number of atmospheric fresh water and organic matter in the relative open system produces the mechanism of the formation of large secondary pores by the common dissolution of feldspar and carbonate minerals by CO_2 and other acidic fluids. The numerical simulation of the dissolution of feldspar - material transfer - secondary mineral precipitation confines the inhomogeneous precipitation of the next mineral (clay minerals and quartz cementation) The numerical simulation experiment and the secondary pore of the feldspar dissolved in the actual geological body and the secondary mineral characteristics clearly define the physical response of the mineral dissolution and the secondary mineral redistribution pattern in the closed diagenesis and the open diagenesis system. The petrological characteristics indicate that the weak dissolution of the feldspar and the carbonate mineral precipitate assemblage can be developed in the clastic reservoir. (I) the combination of feldspar strong dissolution carbonate minerals (II), strong dissolution of feldspar and strong dissolution of carbonate minerals (III), 4 types of feldspar and carbonate mineral assemblages, such as feldspar weak dissolution and strong dissolution of carbonate minerals (IV), the combination of I and II in Shengtuo area, and the combination of III in high willow area. Development. In reservoirs with relatively weak cementation, a weak dissolution of feldspar can be developed - a small amount of clay minerals - a small amount of quartz cementation (I '), weak feldspar dissolution - a large number of clay minerals - a small amount of quartz cementation (II'), massive dissolution of feldspar - A large number of clay minerals - a large number of quartz cementation (III ') and massive dissolving of feldspar. A large amount of clay minerals - a small amount of quartz cementation (IV "), a large amount of feldspar dissolution - a small amount of clay minerals - a small amount of quartz cementation (V") and other 5 types of feldspar dissolution - secondary dissolution product diagenesis, in which combination I 'and III' are bred in Shengtuo area, combination IV is developed in Minfeng Area and combination V 'is high The development of the willow area, II 'can be seen from the chemical equilibrium constant of.CO_2 and CH_3COOH dissolved feldspar and carbonate minerals in the small part of the high willow area and the numerical simulation of water rock reaction under the constraints of thermal dynamics. It is shown that in the potassium feldspar acid -H2O system, the chemical reaction equilibrium constant of the etched potash feldspar is much higher than that in the potassium feldspar acid -H2O system. The chemical reaction equilibrium constant of calcite dissolves, and the dissolving calcite in the same fluid requires a lower pH than the dissolved potassium feldspar, resulting in a stronger dependence of the dissolution of the carbonate minerals on the scale and eroding of the fluid, thus developing the potassium feldspar dissolution in the process of the interaction of the fluid rock phase in the geological time scale. The phenomenon of dissolution (even precipitation). Acid concentration and water volume increase to promote mineral dissolution, ionic salt effect promotes mineral dissolution, and ion effect is used to inhibit mineral dissolution. The dissolution of potassium feldspar can promote the dissolution of potassium feldspar more than the formation of kaolinite in the formation of kaolinite. The fracture of the four segment of the middle Sha 3 middle sand section of Shengtuo area is weak, and the fluid overpressure develops, self The stable isotopes of Mineral Minerals and the chemical characteristics of stratigraphic water indicate that the atmospheric water is weak in the reservoir diagenesis, and the reservoir has a typical relative closed diagenetic system. In this system, the organic matter fermentation of the organic matter in the early diagenetic stage provides carbon source for the early carbonate cementation, resulting in a large number of cementation in the boundary of the interbedded sandstone layers. Precipitation, forming a combination of feldspar weak dissolution and carbonate mineral precipitation; in the middle diagenetic stage, the supply of fresh water is lacking, the water in the stratum is limited, the dissolution of carbonate minerals is suppressed by chemical equilibrium, a large number of CO_2 and organic acids are generated by organic matter and organic acids are formed into the reservoir and selectively dissolved feldspar minerals, forming a large secondary pore. High willow area The fracture system is developed, the fluid overpressure is weak and the development is limited. The stable isotopes of the authigenic minerals and the stratigraphic water chemistry indicate that the reservoir has a strong influence on the atmospheric fresh water during the formation of the reservoir, and the reservoir has a typical relative open diagenetic system. In the stage of uplift and subsequent burial, a large amount of atmospheric fresh water is strongly developed into the middle and deep reservoirs. At the same time, in the middle diagenetic stage, a certain amount of acid fluid is contributed by the thermal deacidification of organic matter. In the relatively high temperature condition of the large-scale water body, the feldspar and carbonate minerals in the reservoirs dissolve at the same time. A large-scale secondary pore is formed. In the sand layer, when the rich CO_2 acid fluid is injected into the sand, the numerical simulation of the coupling feldspar dissolution material transfer and secondary mineral precipitation shows that from upstream to downstream, 3 zones are developed in the sand layer under appropriate conditions: dissolved zone - transition zone - precipitation zone. Dissolved feldspar, no secondary minerals, and transition zone dissolved feldspar. Precipitation of kaolinite; precipitate zone dissolved feldspar, precipitated kaolinite and quartz minerals. The temperature increases, the rate of mineral reaction increases, the velocity of the injection flow decreases and the ion concentration increases to shorten the dissolution zone and the transition zone; the temperature decreases, the mineral reaction rate decreases, the injection flow speed increases and the ion concentration is reduced to the expanded dissolving zone and transition zone. In the undeveloped strata, the near surface low temperature high velocity sand beds tend to form mineral assemblage V ', and the shallow sand beds tend to form mineral assemblage IV', and the middle depth high temperature low velocity sand beds tend to form mineral assemblage III '; the development of fracture growth increases the possibility of mineral assemblage IV and V' in the middle depth sand development. In the relatively closed high temperature and low velocity diagenetic system of the middle diagenetic stage in the Tuo area, the carbonate cements are not (weak) dissolved, while the dissolution products of feldspar particles are quasi situ precipitation, and the secondary pores of the feldspar are secondary pores, and the dissolution can not effectively improve the physical properties of the reservoir. In the high temperature and high velocity open diagenetic system, the feldspar and carbonate minerals are strongly dissolved, and the feldspar dissolution products are effectively taken out of the reservoir, and the secondary pores of the mineral dissolution are the pore type secondary pores, and the dissolution effectively improves the physical properties.
【學(xué)位授予單位】：中國石油大學(xué)(華東)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：P618.13
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本文編號：2023974