围压-孔压改变条件下致密砂岩及泥页岩泊松比变化特征及机制

doi:10.13745/j.esf.sf.2020.12.14

摘要/Abstract

摘要：

在围压(外压)或孔压(内压)发生变化的条件下,致密砂岩及泥页岩泊松比的变化特征及机制仍有待厘清。本研究从Terzaghi有效应力理论和国内学者提出的新有效应力概念出发,基于松辽盆地高台子组致密砂岩、青山口组泥页岩三向动、静态泊松比测定结果,剖析了两类岩石泊松比的变化特征及机制。岩石样品三向泊松比变化曲线的分布呈现显著的各向异性,这将对压裂缝的延展规律产生一定的影响;就“有效应力”概念厘定的科学性而言,“Terzaghi有效应力”适用于裂缝较为发育的储层,而“新有效应力”适用于孔隙度较大且分布较为均匀的泥页岩。结论将为致密油气的有效开发提供较为重要的理论依据。

关键词: 松辽盆地, Terzaghi方程, 有效应力, 泊松比

Abstract:

When the confining pressure (external pressure) or pore pressure (internal pressure) changes, the variation characteristics and mechanism of Poisson’s ratio for tight sandstone and shale still need to be clarified. On the basis of the effective stress theory of Terzaghi and the new concept of effective stress proposed by domestic scholars, this study analyzes the characteristics and mechanism of Poisson’s ratio change based on the dynamic and static Poisson’s ratio measurement results. The rock types consist of tight sandstone of the Gaotaizi Formation and shale of the Qingshankou Formation in the Songliao Basin, respectively. The anisotropic distribution of Poisson’s ratio curves is obvious, which would have some impacts on the propagation law of compression fractures; as far as the scientific definition of “effective stress” is concerned, “Terzaghi effective stress” is suitable for fractured reservoirs while “new effective stress” is suitable for shale with large porosity and uniform pore distribution. The conclusion will provide some important theoretical basis for the effective development of tight oil and gas.

Key words: Songliao Basin, Terzaghi equation, effective stress, Poisson’s ratio;

中图分类号:

TE348
P584

杜书恒, 梁耀欢, 师永民, 关平. 围压-孔压改变条件下致密砂岩及泥页岩泊松比变化特征及机制[J]. 地学前缘, 2021, 28(1): 411-419.

DU Shuheng, LIANG Yaohuan, SHI Yongmin, GUAN Ping. Variations of Poisson’s ratio for tight sandstone and shale under changing confining or pore pressure: Characteristics and mechanism[J]. Earth Science Frontiers, 2021, 28(1): 411-419.

图/表 14

图1 研究区位置示意图

Fig.1 A sketch map of the study area

图2 实验设备(A和B)及取样示意图(C)(根据文献[37]修改)

Fig.2 Experimental equipments (A and B) and sampling scheme (C). Modified from [37].

图3 高台子组致密砂岩储层改变内、外压条件下静态泊松比随新有效应力变化曲线

Fig.3 Cross-plot between the static Possion’s ratio and the “new effective stress” when changing the external (right panel) or internal (left panel) pressure on the Gaotaizi tight sandstone

图4 高台子组致密砂岩储层改变内、外压条件下静态泊松比随Terzaghi有效应力变化曲线

Fig.4 Cross-plot between the static Possion’s ratio and the “Terzaghi effective stress” when changing the external (right panel) or internal (left panel) pressure on the Gaotaizi tight sandstone

图5 高台子组致密砂岩储层改变内、外压条件下动态泊松比随新有效应力变化曲线

Fig.5 Cross-plot between the dynamic Possion’s ratio and the “new effective stress” when changing the external (right panel) or internal (left panel) pressure on the Gaotaizi tight sandstone

图6 高台子组致密砂岩储层改变内、外压条件下动态泊松比随Terzaghi有效应力变化曲线

Fig.6 Cross-plot between the dynamic Possion’s ratio and the “Terzaghi effective stress” when changing the external (right panel) orinternal (left panel) pressure on the Gaotaizi tight sandstone

图7 青山口组泥页岩生油层改变内、外压条件下静态泊松比随新有效应力变化曲线

Fig.7 Cross-plot between the static Possion’s ratio and the “new effective stress” when changing the external (right panel) or internal (left panel) pressure on the Qingshankou source rock of shale

图8 青山口组泥页岩生油层改变内、外压条件下静态泊松比随Terzaghi有效应力变化曲线

Fig.8 Cross-plot between the static Possion’s ratio and the “Terzaghi effective stress” when changing the external (right panel) or internal (left panel) pressure on the Qingshankou source rock of shale

图9 青山口组泥页岩生油层改变内、外压条件下动态泊松比随新有效应力变化曲线

Fig.9 Cross-plot between the dynamic Possion’s ratio and the “new effective stress” when changing the external (right panel) or internal (left panel) pressure on the Qingshankou source rock of shale

图10 青山口组泥页岩生油层改变内、外压条件下动态泊松比随Terzaghi有效应力变化曲线

Fig.10 Cross-plot between the dynamic Possion’s ratio and the “Terzaghi effective stress” when changing the external (right panel) or internal (left panel) pressure on the Qingshankou source rock of shale

表1 高台子组致密砂岩储层泊松比变化规律观察统计

Table 1 Changing rule of Poisson ratio of the Gaotaizi tight sandstone reservoir

储集层泊松比	变化特征描述	改变内压	改变外压
静态泊松比	曲线类型	线性	对数
	曲线组合样式	“1+1+1”	“2+1”
	“新有效应力”下变化率及各向异性	0.007 MPa^-1 (X≈Y≈Z)	0.001 MPa^-1(Y≈Z)+ 0.002/MPa(X)
	“Terzaghi有效应力” 下变化率及各向异性	0.000 5 MPa^-1 (X≈Y≈Z)	0.001 MPa^-1(Y≈Z)+ 0.002 MPa(X)
动态泊松比	曲线类型	线性	线性
	曲线组合样式	“2+1”	“2+1”
	“新有效应力”下变化率及各向异性	0.203 MPa^-1 (X≈Y≈Z)	0.004 MPa^-1(X≈ Y≈Z)
	“Terzaghi有效应力” 下变化率及各向异性	0.004 MPa^-1 (X≈Y≈Z)	0.004 MPa^-1(X≈ Y≈Z)

表2 青山口组泥页岩烃源岩层泊松比变化规律观察统计

Table 2 Changing rule of Poisson ratio of the Qingshankou source rock of shale

烃源岩泊松比	变化特征描述	改变内压	改变外压
静态泊松比	曲线类型	线性	对数(X/Z)+线性(Y)
	曲线组合样式	“2+1”	“1+1+1”
	“新有效应力”下变化率及各向异性	0.010 MPa^-1 (X≈Y≈Z)	0.002 MPa^-1(X)+ 0.000 2 MPa^-1(Y)+ 0.005 MPa^-1(Z)
	“Terzaghi有效应力” 下变化率及各向异性	0.001 MPa^-1 (X≈Y≈Z)	0.002 MPa^-1(X)+ 0.000 2 MPa^-1(Y)+ 0.005 MPa^-1(Z)
动态泊松比	曲线类型	线性	对数(X/Z)+线性(Y)
	曲线组合样式	“1+1+1”	“1+1+1”
	“新有效应力”下变化率及各向异性	0.035 MPa^-1 (X≈Y≈Z)	0.004 MPa^-1 (X≈Y≈Z)
	“Terzaghi有效应力”下变化率及各向异性	0.004 MPa^-1 (X≈Y≈Z)	0.004 MPa^-1 (X≈Y≈Z)

图11 高台子组致密砂岩储层实物样品扫描电镜下的微观特征

Fig.11 The microscopic characteristics of the Gaotaizi tight sandstone reservoir under the scanning electron microscopy (SEM)

图12 青山口组泥页岩生油层实物样品扫描电镜下的微观特征

Fig.12 The microscopic characteristics of the Qingshankou source rock of shale under the scanning electron microscopy (SEM)

参考文献 43

[1]	HUANG Z Q, ZHANG X Y, YAO J, et al. Non-Darcy displacement by a non-Newtonian fluid in porous media according to the Barree-Conway model[J]. Advances in Geo-Energy Research, 2017, 1(2):74-85. DOI URL
[2]	李道伦, 齐银, 达引朋, 等. 低速非线性是低渗油藏的流动机制[J]. 非常规油气, 2020, 7(4):1-8.
[3]	WAN Y W, ZHANG H, LIU X J, et al. Prediction of mechanical parameters for low-permeability gas reservoirs in the Tazhong Block and its applications[J]. Advances in Geo-Energy Research, 2020, 4(2):219-228. DOI URL
[4]	贾光亮, 吴天乾, 李晔旻, 郑道明. 临兴低压浅层气压裂改造技术研究与应用[J]. 非常规油气, 2020, 7(3):101-107.
[5]	LU M J, SU Y L, ZHAN S Y, et al. Modeling for reorientation and potential of enhanced oil recovery in refracturing[J]. Advances in Geo-Energy Research, 2020, 4(1):20-28. DOI URL
[6]	WOOD D A. Establishing credible reaction-kinetics distributions to fit and explain multi-heating rate S2 pyrolysis peaks of kerogens and shales[J]. Advances in Geo-Energy Research, 2019, 3(1):1-28. DOI URL
[7]	谢明英, 戴宗, 罗东红, 等. 基于微米CT扫描驱替实验的稠油油藏剩余油特征分析新方法[J]. 非常规油气, 2020, 7(5):102-107.
[8]	祝金利. 强非均质致密砂岩气藏剩余气分布定量描述与挖潜对策: 以苏里格气田苏11区块北部老区为例[J]. 天然气工业, 2020, 40(11):89-95.
[9]	白远, 康胜松, 云彦舒, 等. 基于高温岩电实验的致密砂岩储层含油饱和度解释方法研究: 以鄂尔多斯盆地南部延长组长8致密储层为例[J]. 非常规油气, 2019, 6(6):68-73.
[10]	张海杰, 蒋裕强, 周克明, 等. 页岩气储层孔隙连通性及其对页岩气开发的启示: 以四川盆地南部下志留统龙马溪组为例[J]. 天然气工业, 2019, 39(12):22-31.
[11]	赵伦, 陈烨菲, 宁正福, 等异常高压碳酸盐岩油藏应力敏感实验评价: 以滨里海盆地肯基亚克裂缝-孔隙型低渗透碳酸盐岩油藏为例[J]. 石油勘探与开发, 2013, 40(2):194-200.
[12]	骆杨, 赵彦超, 陈红汉, 等. 构造应力-流体压力耦合作用下的裂缝发育特征: 以渤海湾盆地东濮凹陷柳屯洼陷裂缝性泥页岩“油藏”为例[J]. 石油勘探与开发, 2015, 42(2):177-185.
[13]	王敬, 刘慧卿, 刘仁静, 等. 考虑启动压力和应力敏感效应的低渗、特低渗油藏数值模拟研究[J]. 岩石力学与工程学报, 2013, 32(增刊2):3317-3327.
[14]	冉启全, 顾小芸. 油藏渗流与应力耦合分析[J]. 岩土工程学报, 1998, 20(2):69-73.
[15]	洪亮, 刘雄志, 杨兆平, 等. 对多孔介质双重有效应力理论的讨论[J]. 新疆石油地质, 2014, 35(6):732-737.
[16]	赵成刚, 刘真真, 李舰, 等. 土力学有效应力及其作用的讨论[J]. 力学学报, 2015, 47(2):356-361. DOI
[17]	邵龙潭, 郭晓霞, 郑国锋. 粒间应力、土骨架应力和有效应力[J]. 岩土工程学报, 2015, 37(8):1478-1483.
[18]	路德春, 杜修力, 许成顺. 有效应力原理解析[J]. 岩土工程学报, 2013, 35(增刊1):146-151.
[19]	雷国辉, 陈晶晶. 有效应力决定饱和岩土材料抗剪强度的摩擦学解释[J]. 岩土工程学报, 2011, 33(10):1517-1525.
[20]	陈正汉, 秦冰. 非饱和土的应力状态变量研究[J]. 岩土力学, 2012, 33(1):1-11.
[21]	李传亮. 关于双重有效应力: 回应洪亮博士[J]. 新疆石油地质, 2015, 36(2):238-243.
[22]	李传亮. 有效应力概念的误用[J]. 天然气工业, 2008, 28(10):130-132.
[23]	李传亮, 朱苏阳. 关于应力敏感测试方法的认识误区[J]. 岩性油气藏, 2015, 27(6):1-4.
[24]	李传亮. 多孔介质的应力关系方程: 答周大晨先生[J]. 新疆石油地质, 2002, 23(2):163-164.
[25]	周大晨. 对李传亮上覆岩层压力公式的质疑[J]. 新疆石油地质, 2001, 22(2):150-154.
[26]	DU S H, SHI Y M, GUAN P, et al. New inspiration on effective development of tight reservoir in secondary exploitation by using rock mechanics method[J]. Energy Exploration & Exploitation, 2016, 34(1):1-16.
[27]	杜书恒, 师永民. 低渗油气藏水力压裂理想水驱波及范围预测新方法[J]. 天然气地球科学, 2015, 26(10):1956-1962.
[28]	卜向前, 师永民, 杜书恒, 等. 低渗透油藏压力场变化对岩体力学性质的影响[J]. 北京大学学报(自然科学版), 2015, 51(5):850-856.
[29]	胡伟光, 蒲勇, 赵卓男, 等. 利用弹性参数预测礁、滩相储层[J]. 石油地球物理勘探, 2010, 45(增刊1):176-180.
[30]	刘钦节. 低渗油藏储层裂缝的参数反分析优化方法研究[D]. 北京: 中国石油大学, 2009.
[31]	贺顺义. 大庆外围低渗透油藏应力场恢复模拟及裂缝预测[D]. 北京: 中国地质大学(北京), 2010.
[32]	樊长江, 王贤. 泊松比岩性预测方法研究: 以准噶尔盆地为例[J]. 石油勘探与开发, 2006, 33(3):299-302.
[33]	许卫卫, 郑天愉. 渤海湾盆地北西盆山边界地区泊松比分布[J]. 地球物理学报, 2005, 48(5):1077-1084.
[34]	杜书恒, 师永民, 徐启, 等. 井震联合非均质储层改造规模的非线性表征方法[J]. 北京大学学报(自然科学版), 2016, 52(2):241-248.
[35]	DU S H, SHI Y M, BU X Q, et al. New expression of the changing stress field in low-permeability reservoir and its application in secondary exploitation[J]. Energy Exploration & Exploitation, 2015, 33(4):491-514.
[36]	杜书恒, 关平, 师永民, 等. 低渗透砂岩储层可压裂性新判据[J]. 地学前缘, 2017, 24(2):257-264.
[37]	杜书恒, 师永民, 关平等. 松辽盆地扶余低渗储层压裂缝定量预测[J]. 地学前缘, 2017, 24(6):381-389.
[38]	杜书恒, 赵晔, 庞姗, 等. 岩石水力压裂微观破裂机制[J]. 天然气地球科学, 2016, 27(12):2237-2245.
[39]	郭培峰, 邓虎成, 邓勇, 等. 鄂尔多斯盆地南缘长8储层岩石力学特征及影响因素[J]. 科学技术与工程, 2019, 19(18):189-198.
[40]	石玉江, 么勃卫, 夏宏泉. 致密油储层岩石各向异性的动态声学实验研究[J]. 测井技术, 2019, 43(3):228-234.
[41]	桂俊川, 陈平, 马天寿. 正交各向异性岩石弹性参数的空间展布[J]. 西南石油大学学报(自然科学版), 2019, 41(3):13-28.
[42]	王国栋, 程日辉, 王璞珺, 等. 松辽盆地嫩江组白云岩形成机理: 以松科1井南孔为例[J]. 地质学报, 2008, 82(1):48-54.
[43]	王磊. 基于非均质岩石力学模型的水力压裂数值模拟[D]. 北京: 北京大学, 2016.