桩海地区下古生界碳酸盐岩表生条件下溶蚀过程模拟实验
|
摘要
模拟表生条件下(22℃、1.0 MPa)岩石溶蚀过程,采用0.2%的盐酸溶液分别对桩海地区下古生界6种不同类型的碳酸盐岩进行溶蚀实验,结合扫描电镜观察与离子浓度分析手段,对比研究了表生条件下大气淡水对不同类型碳酸盐岩的溶蚀差异。实验结果表明,岩石组构和矿物成分都存在选择性溶蚀,白云石多溶蚀成蜂窝状,方解石则可经溶蚀呈晶锥状;溶蚀率排序为白云质灰岩>泥质白云岩>鲕粒灰岩>灰岩>灰质白云岩>白云岩,灰岩类Ca2+、Mg2+释放合量6.35～7.08 mmol/L,明显高于白云岩类Ca2+、Mg2+的释放合量6.005～6.368 mmol/L,整体上灰岩类溶蚀率大于白云岩类,溶蚀率最高的白云质灰岩由于有少量白云石的加入促进了方解石的溶解,改善储层溶蚀效果。实际地质条件下,常规测井、成像测井以及钻录井数据显示,灰岩类地层溶蚀孔洞发育,其溶蚀的规模与强度都大于白云岩类。总体看来,实际地质条件下的碳酸盐岩溶蚀特征与本次水-岩实验结果一致,表生大气水条件下灰岩类比白云岩类易溶,其中,白云质灰岩最易溶。
In this study, we use a 0.2% hydrochloric acid solution to dissolve different types of the Lower Paleozoic carbonate rocks in the Zhuanghai Area of Shengli Oilfield in order to simulate the dissolution process of carbonate rocks under supergene conditions(22 ℃, 1.0 MPa). The scanning electron microscopy observation and ion concentration analysis have been applied to study differences among the dissolution of different types of carbonate rocks by atmospheric fresh water under supergene conditions. The experimental results show that selective dissolution occurred due to both rock structures and mineral compositions. After the dissolution by water, the residual dolomite mostly has honeycomb structure, while the residual calcite has crystal cone drusy structure. The dissolution rate ranking is subsequently decreased in following order: dolomitic limestone > argillaceous dolomite > oolitic limestone > limestone > gray dolomite > dolomite. The contents of Ca2+ and Mg2+ released from limestone vary from 6.35 to 7.08 mmol/L, which is significantly higher than those from dolomite(6.005 to 6.368 mmol/L). The overall dissolution rate of limestone is greater than that of dolomite. The reason why dolomitic limestone has the highest dissolution rate is because the small amount of dolomite in dolomitic limestone has facilitated the dissolution of calcite and improved the dissolution effect of reservoir. Under natural geological condition, data of the conventional log, imaging log, and drilling log show that dissolution pores and holes are developed in limestones because their dissolution scale and strength are larger than those of dolomites. Overall, the karst corrosion characteristics of carbonates in natural geological condition are consistent with the results of water-rock experiments in this study. In conclusion, the limestone is easier to be dissolved than the dolomite under the condition of supergene atmospheric water. Especially, the dolomitic limestone can be most easily dissolved.
In this study, we use a 0.2% hydrochloric acid solution to dissolve different types of the Lower Paleozoic carbonate rocks in the Zhuanghai Area of Shengli Oilfield in order to simulate the dissolution process of carbonate rocks under supergene conditions(22 ℃, 1.0 MPa). The scanning electron microscopy observation and ion concentration analysis have been applied to study differences among the dissolution of different types of carbonate rocks by atmospheric fresh water under supergene conditions. The experimental results show that selective dissolution occurred due to both rock structures and mineral compositions. After the dissolution by water, the residual dolomite mostly has honeycomb structure, while the residual calcite has crystal cone drusy structure. The dissolution rate ranking is subsequently decreased in following order: dolomitic limestone > argillaceous dolomite > oolitic limestone > limestone > gray dolomite > dolomite. The contents of Ca2+ and Mg2+ released from limestone vary from 6.35 to 7.08 mmol/L, which is significantly higher than those from dolomite(6.005 to 6.368 mmol/L). The overall dissolution rate of limestone is greater than that of dolomite. The reason why dolomitic limestone has the highest dissolution rate is because the small amount of dolomite in dolomitic limestone has facilitated the dissolution of calcite and improved the dissolution effect of reservoir. Under natural geological condition, data of the conventional log, imaging log, and drilling log show that dissolution pores and holes are developed in limestones because their dissolution scale and strength are larger than those of dolomites. Overall, the karst corrosion characteristics of carbonates in natural geological condition are consistent with the results of water-rock experiments in this study. In conclusion, the limestone is easier to be dissolved than the dolomite under the condition of supergene atmospheric water. Especially, the dolomitic limestone can be most easily dissolved.
引文
[1]袁静.埕北30区块潜山油气藏下古生界储层特征[J].天然气工业,2004,24(11):22-25.
[2]林会喜.济阳坳陷桩西埕岛地区下古生界潜山储层岩溶作用[J].成都理工大学学报(自然科学版),2004,31(5):490-497.
[3]崔殿,许淑梅,王金铎,等.桩海地区下古生界古潜山碳酸盐岩孔隙特征与空间组合规律[J].海洋地质与第四纪地质,2008,28(3):93-102.
[4]王永诗.桩西-埕岛地区下古生界潜山储集层特征及形成机制[J].岩性油气藏,2009,21(1):11-14.
[5]Plummer L N,Wigley T M L,Parkhurst D L.The kinetics of calcite dissolution in CO2-water systems at 5 to 60℃and 0.0 to 1.0 atm CO2[J].Am JSci,1978,278(2):179-216.
[6]Pokrovsky O S,Golubev S V,Schott J.Dissolution kinetics of calcite,dolomite and magnesite at 25℃and 0 to 50 atm pCO2[J].Chem Geol,2005,217(3/4):239-255.
[7]宋焕荣,黄尚瑜.碳酸盐岩与岩溶[J].矿物岩石,1988,8(1):9-17.
[8]翁金桃.方解石和白云石的差异溶蚀作用[J].中国岩溶,1984,3(1):29-38.
[9]杨俊杰,黄思静,张文正,等.表生和埋藏成岩作用的温压条件下不同组成碳酸盐岩溶蚀成岩过程的实验模拟[J].沉积学报,1995,13(4):49-54.
[10]钱一雄,Conxita T,邹森林,等.碳酸盐岩表生岩溶与埋藏溶蚀比较:以塔北和塔中地区为例[J].海相油气地质,2007,12(2):1-7.
[11]范明,蒋小琼,刘伟新,等.不同温度条件下CO2水溶液对碳酸盐岩的溶蚀作用[J].沉积学报,2007,25(6):825-830.
[12]佘敏,寿建峰,贺训云,等.碳酸盐岩溶蚀机制的实验探讨:表面溶蚀与内部溶蚀对比[J].海相油气地质,2013,18(3):55-61.
[13]佘敏,寿建峰,沈安江,等.从表生到深埋环境下有机酸对碳酸盐岩溶蚀的实验模拟[J].地球化学,2014,43(3):276-286.
[14]朱文慧,曲希玉,邱隆伟,等.盐酸及乙酸介质中的碳酸盐岩溶蚀表面特征及机理-以南堡凹陷为例[J].矿物岩石地球化学通报,2015,34(3):619-625.
[15]徐国盛,李国蓉,王志雄.济阳坳陷下古生界潜山储集体特征[J].石油与天然气地质,2002,23(3):248-251.
[16]聂继红,韩宝平,高澜.碳酸盐矿物的微观喀斯特研究[J].分析测试技术与仪器,1995,1(2):33-37.
[17]韩宝平.喀斯特微观溶蚀机理研究[J].中国岩溶,1993,12(2):97-102.
[18]Reuch H W,White W B.Dissolution kinetics of carbonate rocks:1.Effects of lithology on dissolution rate[J].Water Resources Research,1977,13(2):381-394.
[19]宋焕荣,等.喀斯特发育过程中的化学溶解和物理破坏作用、喀斯特地貌与洞穴研究[M].北京:科学出版社,1990:171-181.
[20]Davis K J,Dove P M,Yoreo J J D.The Role of Mg2+as an impurity in calcite growth[J].Science,2000,290:1134-1137.
[21]Picknett R G,Stenner R O.Enhanced calcite solubility in dilute magnesium carbonate solutions[M].London:Transactions of the British Cave Research Association,1978,5(1):47-54.
[22]谭俊敏,李明娟,等.济阳坳陷早古生代层序划分与石油地质条件[J].新疆石油地质,2007,28(3):308-313.
[2]林会喜.济阳坳陷桩西埕岛地区下古生界潜山储层岩溶作用[J].成都理工大学学报(自然科学版),2004,31(5):490-497.
[3]崔殿,许淑梅,王金铎,等.桩海地区下古生界古潜山碳酸盐岩孔隙特征与空间组合规律[J].海洋地质与第四纪地质,2008,28(3):93-102.
[4]王永诗.桩西-埕岛地区下古生界潜山储集层特征及形成机制[J].岩性油气藏,2009,21(1):11-14.
[5]Plummer L N,Wigley T M L,Parkhurst D L.The kinetics of calcite dissolution in CO2-water systems at 5 to 60℃and 0.0 to 1.0 atm CO2[J].Am JSci,1978,278(2):179-216.
[6]Pokrovsky O S,Golubev S V,Schott J.Dissolution kinetics of calcite,dolomite and magnesite at 25℃and 0 to 50 atm pCO2[J].Chem Geol,2005,217(3/4):239-255.
[7]宋焕荣,黄尚瑜.碳酸盐岩与岩溶[J].矿物岩石,1988,8(1):9-17.
[8]翁金桃.方解石和白云石的差异溶蚀作用[J].中国岩溶,1984,3(1):29-38.
[9]杨俊杰,黄思静,张文正,等.表生和埋藏成岩作用的温压条件下不同组成碳酸盐岩溶蚀成岩过程的实验模拟[J].沉积学报,1995,13(4):49-54.
[10]钱一雄,Conxita T,邹森林,等.碳酸盐岩表生岩溶与埋藏溶蚀比较:以塔北和塔中地区为例[J].海相油气地质,2007,12(2):1-7.
[11]范明,蒋小琼,刘伟新,等.不同温度条件下CO2水溶液对碳酸盐岩的溶蚀作用[J].沉积学报,2007,25(6):825-830.
[12]佘敏,寿建峰,贺训云,等.碳酸盐岩溶蚀机制的实验探讨:表面溶蚀与内部溶蚀对比[J].海相油气地质,2013,18(3):55-61.
[13]佘敏,寿建峰,沈安江,等.从表生到深埋环境下有机酸对碳酸盐岩溶蚀的实验模拟[J].地球化学,2014,43(3):276-286.
[14]朱文慧,曲希玉,邱隆伟,等.盐酸及乙酸介质中的碳酸盐岩溶蚀表面特征及机理-以南堡凹陷为例[J].矿物岩石地球化学通报,2015,34(3):619-625.
[15]徐国盛,李国蓉,王志雄.济阳坳陷下古生界潜山储集体特征[J].石油与天然气地质,2002,23(3):248-251.
[16]聂继红,韩宝平,高澜.碳酸盐矿物的微观喀斯特研究[J].分析测试技术与仪器,1995,1(2):33-37.
[17]韩宝平.喀斯特微观溶蚀机理研究[J].中国岩溶,1993,12(2):97-102.
[18]Reuch H W,White W B.Dissolution kinetics of carbonate rocks:1.Effects of lithology on dissolution rate[J].Water Resources Research,1977,13(2):381-394.
[19]宋焕荣,等.喀斯特发育过程中的化学溶解和物理破坏作用、喀斯特地貌与洞穴研究[M].北京:科学出版社,1990:171-181.
[20]Davis K J,Dove P M,Yoreo J J D.The Role of Mg2+as an impurity in calcite growth[J].Science,2000,290:1134-1137.
[21]Picknett R G,Stenner R O.Enhanced calcite solubility in dilute magnesium carbonate solutions[M].London:Transactions of the British Cave Research Association,1978,5(1):47-54.
[22]谭俊敏,李明娟,等.济阳坳陷早古生代层序划分与石油地质条件[J].新疆石油地质,2007,28(3):308-313.