川西南部须二气藏压裂理论与工艺技术研究
|
摘要
川西南部地区须家河地层分布范围广,含气面积大,其中主要含气层段为须二。川西须家河地区存在多种原因导致水力加砂压裂改造的难度很大：储层埋藏深,破裂压力高；储层天然裂缝发育,滤失严重,为了降滤失、防砂堵,需大排量施工,导致施工压力高；储层岩性细砂岩,细粒,硅质胶结,较硬,岩石杨氏模量高,形成的裂缝较窄,为了防止砂堵也需大排量施工,从而也将导致施工压力较高；而储层较深,管路摩阻大,可能会受施工压力的限制而无法提高排量导致压裂施工失败。从须二低渗气藏的开发来看,目前尚未形成一套较为有效的储层改造措施,低渗气藏开发配套技术和开发效果缺乏突破性的进展。
本文针对川西须二气藏压裂理论与工艺技术方面进行了系统研究,取得了以下主要成果：
(1)应用测井资料、室内岩石力学实验测试和压裂施工资料,反演获得该区块构造应力系数,建立起分层地应力的力学模型的方法,获得了纵向分层应力剖面。
(2)综合利用岩石力学、弹性力学等知识,建立了射孔完井条件下以及储层受到伤害后的储层破裂压力定量预测模型,为降低施工风险和优化施工工艺提供了依据。
(3)依据须家河气藏储层物性条件,提出了须家河气藏压裂液体系的性能要求,通过室内实验优选了中高温低摩阻压裂液添加剂,并对优化、调试的压裂液体系进行了综合性能评价。
(4)系统阐述了多裂缝的形成机理及多裂缝的消除技术,并结合川西须家河的地质特征和工程实际,研究了须家河气藏多裂缝的形成机理和包括支撑剂段塞、压裂材料选择、施工参数优化在内的多种降滤失与多裂缝防治的工艺技术。
(5)针对高破裂压力储层提出了多项降低破裂压力技术,并对每种技术的适应性进行了分析。
Xujiahe formation, which has a large gas-bearing area, are widely dispersed in southwestern Sichuan, and its main gas-bearing section is t3x2. There are many reasons in Xujiahe areas lead to extremely difficulties for sand hydraulic fracturing. The deep lying formation have a high fracturing pressure. Natural fractures develop, and filtrate seriously. It requied work with large displacement to lower filtration, and to prevent sand blocking. Thus, the treating pressure would be very high. Formation is a fine sandstone lithology. They form narrow fractures because of their hard feature and high Young's modulus. It needs work with large displacement for sand blocking prevention, which is also lead to high treating pressure. The reservoir buried deep, and the pipe friction is large, whereas the treating pressure is limited, which induce the displacement couldn't be increased to the required value. Seen from the exploitation of t3x2 low permeability gas reservoir, an efficient Reservoir reconstruction measures not yet formed currently. Supporting technologies and effect of low permeability gas reservoir development lack a breakthrough.
The present paper is specific to fracturing theory and technology of t3x2 gas reservoir in western Sichuan. We got the tectonic stress coefficient with logging data, experimental data of rock mechanics testing and fracturing treating data, set up a mechanical model for the stratified calculation of ground stress, and obtained the vertical stratification stress profile. By utilization of rock mechanics, elasticity and other knowledge, we set up a model for quantitative prediction of formation breakdown pressure for perforation completions of vertical wells while the reservoir was injuried, which Provided a basis for lowering treating risk and optimizing the technology. According to the physical conditions of t3x2 gas reservoir, we put-forward the requirements for fracturing fluid system performance, optimized low-friction and high temperature fracturing fluid additives, and envaluated the optimized fracturing fluid system. The study illustrated the formation mechanism and cancellation of multiple fractures Systematically, and investigated the formation mechanism of multiple fractures, various technologies including proppant slug, fracturing material selection and optimization of construction parameters for lowering filtration and fractures prevention combined with geological features of Xujiahe aera and reality of the project. Besides that, we came up with several technologies for lowering fracturing pressure for high fracturing pressure reservoir, and analyzed their adaptability.
本文针对川西须二气藏压裂理论与工艺技术方面进行了系统研究,取得了以下主要成果：
(1)应用测井资料、室内岩石力学实验测试和压裂施工资料,反演获得该区块构造应力系数,建立起分层地应力的力学模型的方法,获得了纵向分层应力剖面。
(2)综合利用岩石力学、弹性力学等知识,建立了射孔完井条件下以及储层受到伤害后的储层破裂压力定量预测模型,为降低施工风险和优化施工工艺提供了依据。
(3)依据须家河气藏储层物性条件,提出了须家河气藏压裂液体系的性能要求,通过室内实验优选了中高温低摩阻压裂液添加剂,并对优化、调试的压裂液体系进行了综合性能评价。
(4)系统阐述了多裂缝的形成机理及多裂缝的消除技术,并结合川西须家河的地质特征和工程实际,研究了须家河气藏多裂缝的形成机理和包括支撑剂段塞、压裂材料选择、施工参数优化在内的多种降滤失与多裂缝防治的工艺技术。
(5)针对高破裂压力储层提出了多项降低破裂压力技术,并对每种技术的适应性进行了分析。
Xujiahe formation, which has a large gas-bearing area, are widely dispersed in southwestern Sichuan, and its main gas-bearing section is t3x2. There are many reasons in Xujiahe areas lead to extremely difficulties for sand hydraulic fracturing. The deep lying formation have a high fracturing pressure. Natural fractures develop, and filtrate seriously. It requied work with large displacement to lower filtration, and to prevent sand blocking. Thus, the treating pressure would be very high. Formation is a fine sandstone lithology. They form narrow fractures because of their hard feature and high Young's modulus. It needs work with large displacement for sand blocking prevention, which is also lead to high treating pressure. The reservoir buried deep, and the pipe friction is large, whereas the treating pressure is limited, which induce the displacement couldn't be increased to the required value. Seen from the exploitation of t3x2 low permeability gas reservoir, an efficient Reservoir reconstruction measures not yet formed currently. Supporting technologies and effect of low permeability gas reservoir development lack a breakthrough.
The present paper is specific to fracturing theory and technology of t3x2 gas reservoir in western Sichuan. We got the tectonic stress coefficient with logging data, experimental data of rock mechanics testing and fracturing treating data, set up a mechanical model for the stratified calculation of ground stress, and obtained the vertical stratification stress profile. By utilization of rock mechanics, elasticity and other knowledge, we set up a model for quantitative prediction of formation breakdown pressure for perforation completions of vertical wells while the reservoir was injuried, which Provided a basis for lowering treating risk and optimizing the technology. According to the physical conditions of t3x2 gas reservoir, we put-forward the requirements for fracturing fluid system performance, optimized low-friction and high temperature fracturing fluid additives, and envaluated the optimized fracturing fluid system. The study illustrated the formation mechanism and cancellation of multiple fractures Systematically, and investigated the formation mechanism of multiple fractures, various technologies including proppant slug, fracturing material selection and optimization of construction parameters for lowering filtration and fractures prevention combined with geological features of Xujiahe aera and reality of the project. Besides that, we came up with several technologies for lowering fracturing pressure for high fracturing pressure reservoir, and analyzed their adaptability.
引文
[1]李文魁.致密气藏的开采与工艺技术[J].钻采工艺,2002,25(1).
[2]刘同斌.四川油气田压裂酸化液技术新进展[J].石油与天然气化工,2002,31(2).
[3]范文敏.国外压后返排的理论研究与推荐作法三[J].钻采工艺,2000,23(5).
[4]李文魁.压裂液流变性研究的新进展[J].西安石油学院学报,2000,15(2).
[5]沈宇.无聚合物压裂液[J].吉林石油科技,2000,12(2).
[6]胡奥林.90年代国外低渗透油田增产工艺技术[J].世界石油工业,1999,6(9)
[7]罗英俊,万仁溥主编.采油技术手册(修订本),北京：石油工业出版社,2002.
[8]焦国盈.压裂充填防砂与增产技术研究.西南石油学院博士学位论文,2005,4：81-84.
[9]段永刚,陈伟,熊友明,等.油气层损害定时分析和评价.西南石油学院学报,2001,23(2)：44-46.
[10]成绥民,王天顺.表皮系数系统分解方法.钻采工艺,1991,14(4)：35-40.
[11]李毓,王洪辉,李楠等1川西坳陷中部现今地应力纵向分布规律研究及应用[J]1天然气工业,2005,25(11)：43-441
[12]王鸿勋,张琪主编,采油工艺原理(修订本).北京：石油工业出版社,1989.
[13]李传亮,孔祥言,徐献芝,李培超著.多孔介质的双重有效应力.自然杂志,1999,21(5)：288-292
[14]米卡尔J.埃克诺米德斯.肯尼斯G诺尔特著.张保平等译.油藏增产措施(第三版).北京：石油工业出版社,2002.
[15]张芳,赵炜,李发荣.碳酸盐岩气藏的酸化压裂技术.国外油田工程.2005,21(1).
[16]Detournay E, Carbonell R. Fracture-Mechanics Analysis of the Break down Process in Minifracture or Leakoff Test. SPE Production & Facilities,August 1997:195-199.
[17]Haimson B,Fairhurst C.Initiation and Extension of Hydraulic Fractures in Rocks. SPEJ, Sept.1967:310-318.
[18]Michael Walker, Walter Dill.Iron Control in West Texas Sour-Gas Wells Provides Sustained Production Increases. JPT, May,1991.
[19]Jack D. Lynn, H. A. Nasr-El-Din. A core based comparison of the reaction characteristics of emulsified and in-situ gelled acids in low permeability, high temperature, gas bearing carbonates. SPE 65386
[20]H.A. Nasr-El-Din, J.R. Solares, et al. Field Application of Emulsified Acid-Based System to Stimulate Deep, Sour Gas Reservoirs in Saudi Arabia. SPE 71693.
[21]H.A. Nasr-El-Din, J.D. Lynn, et al. Field Application of a Novel Emulsified Scale Inhibitor System to Mitigate Calcium Carbonate Scale in a Low Temperature, Low Pressure Sandstone Reservoir in Saudi Arabia. SPE 77768
[22]H.A. Nasr-El-Din, S.H. Al-Mutairi, W. Walters. Stimulation of a Deep Sour Gas Reservoir Using Gelled Acid. SPE 75501.
[23]N.A. Mclnnis, T.A. Harting, J.D. Vaitl. Evolution of Completion Practices and Wellbore Geometry:A sour Carbonate Reservoir in the Wyoming Thrustbelt. SPE75682.
[24]Ding Yunhong 1A case study of massive hydraulic f ract uring in an ult ra2deep gas well [J] 1 SPE 88613,20041
[25]青永固 1 川西致密碎屑岩气藏水力压裂工艺技术进展[J]1天然气工业,2002,22(3)：21-241
[26]Wang Zhenduo 1 Development and research on f ract uring technology in low2permeability ult ra2deep well s in China [J] 1 SPE 64492,2001
[27]胡明毅,李士祥,魏国齐等1川西前陆盆地上三叠统须家河组致密砂岩储层评价[J]1天然气地球科学,2006,17(4)：456-4581
[28]Frederic J r et al. New correlations to predict non2darcy flowcoefficients at immobile and mobile water saturation. SPE28451,1994
[29]Whitsit t N F and Dysart G R. The effect of temperatureon stimulation design[J]. J PT,1970:493～502.
[30]Dysart G R and Whitsit t N F. Fluid Temperature in Frac2ture[J]. SPE,1902.
[31]Wheeler J A. Analytical calculation of heat Transfer f romFractures[J]. SPE, 2494.
[32]Ben-Naceur K and Stephenson P. Models of heat t rans 2fer in hydraulic f racturing[J]. SPE,13865.
[33]刘蜀知,任书泉.三维水力压裂裂缝中的温度场模型[J].低渗透油气田,1996,1(2)；47-50.
[34]HossainM M, RahmanM K, Rahman S S. A comp rehen2sive monograph for hydraulic fracture initiati on from devi2ated wellbores under arbitrary stress regi mes[C]. SPE54360,1999.
[35]Nishika T,Atluri S N. A si mple esti mati on method of stressintensity fact ors for thr ough2 cracks in angle2 plylaminates[J]. Engineering FractureMechanics, 1982,16 (4):23-28.
[36]Stephen,Daines R. Predicti on of fracture pressure for wildwell[J]. Journal of Petr oleum Technol ogy,1982,4:211-223.
[37]Parihar K S, S owdamini S. Stress distributi on in the neighbourhood of griffith and external cracks under generalsurface 1 oadings[J], Engineering Fracture Mechanics,1982,16 (4):72-86.
[2]刘同斌.四川油气田压裂酸化液技术新进展[J].石油与天然气化工,2002,31(2).
[3]范文敏.国外压后返排的理论研究与推荐作法三[J].钻采工艺,2000,23(5).
[4]李文魁.压裂液流变性研究的新进展[J].西安石油学院学报,2000,15(2).
[5]沈宇.无聚合物压裂液[J].吉林石油科技,2000,12(2).
[6]胡奥林.90年代国外低渗透油田增产工艺技术[J].世界石油工业,1999,6(9)
[7]罗英俊,万仁溥主编.采油技术手册(修订本),北京：石油工业出版社,2002.
[8]焦国盈.压裂充填防砂与增产技术研究.西南石油学院博士学位论文,2005,4：81-84.
[9]段永刚,陈伟,熊友明,等.油气层损害定时分析和评价.西南石油学院学报,2001,23(2)：44-46.
[10]成绥民,王天顺.表皮系数系统分解方法.钻采工艺,1991,14(4)：35-40.
[11]李毓,王洪辉,李楠等1川西坳陷中部现今地应力纵向分布规律研究及应用[J]1天然气工业,2005,25(11)：43-441
[12]王鸿勋,张琪主编,采油工艺原理(修订本).北京：石油工业出版社,1989.
[13]李传亮,孔祥言,徐献芝,李培超著.多孔介质的双重有效应力.自然杂志,1999,21(5)：288-292
[14]米卡尔J.埃克诺米德斯.肯尼斯G诺尔特著.张保平等译.油藏增产措施(第三版).北京：石油工业出版社,2002.
[15]张芳,赵炜,李发荣.碳酸盐岩气藏的酸化压裂技术.国外油田工程.2005,21(1).
[16]Detournay E, Carbonell R. Fracture-Mechanics Analysis of the Break down Process in Minifracture or Leakoff Test. SPE Production & Facilities,August 1997:195-199.
[17]Haimson B,Fairhurst C.Initiation and Extension of Hydraulic Fractures in Rocks. SPEJ, Sept.1967:310-318.
[18]Michael Walker, Walter Dill.Iron Control in West Texas Sour-Gas Wells Provides Sustained Production Increases. JPT, May,1991.
[19]Jack D. Lynn, H. A. Nasr-El-Din. A core based comparison of the reaction characteristics of emulsified and in-situ gelled acids in low permeability, high temperature, gas bearing carbonates. SPE 65386
[20]H.A. Nasr-El-Din, J.R. Solares, et al. Field Application of Emulsified Acid-Based System to Stimulate Deep, Sour Gas Reservoirs in Saudi Arabia. SPE 71693.
[21]H.A. Nasr-El-Din, J.D. Lynn, et al. Field Application of a Novel Emulsified Scale Inhibitor System to Mitigate Calcium Carbonate Scale in a Low Temperature, Low Pressure Sandstone Reservoir in Saudi Arabia. SPE 77768
[22]H.A. Nasr-El-Din, S.H. Al-Mutairi, W. Walters. Stimulation of a Deep Sour Gas Reservoir Using Gelled Acid. SPE 75501.
[23]N.A. Mclnnis, T.A. Harting, J.D. Vaitl. Evolution of Completion Practices and Wellbore Geometry:A sour Carbonate Reservoir in the Wyoming Thrustbelt. SPE75682.
[24]Ding Yunhong 1A case study of massive hydraulic f ract uring in an ult ra2deep gas well [J] 1 SPE 88613,20041
[25]青永固 1 川西致密碎屑岩气藏水力压裂工艺技术进展[J]1天然气工业,2002,22(3)：21-241
[26]Wang Zhenduo 1 Development and research on f ract uring technology in low2permeability ult ra2deep well s in China [J] 1 SPE 64492,2001
[27]胡明毅,李士祥,魏国齐等1川西前陆盆地上三叠统须家河组致密砂岩储层评价[J]1天然气地球科学,2006,17(4)：456-4581
[28]Frederic J r et al. New correlations to predict non2darcy flowcoefficients at immobile and mobile water saturation. SPE28451,1994
[29]Whitsit t N F and Dysart G R. The effect of temperatureon stimulation design[J]. J PT,1970:493～502.
[30]Dysart G R and Whitsit t N F. Fluid Temperature in Frac2ture[J]. SPE,1902.
[31]Wheeler J A. Analytical calculation of heat Transfer f romFractures[J]. SPE, 2494.
[32]Ben-Naceur K and Stephenson P. Models of heat t rans 2fer in hydraulic f racturing[J]. SPE,13865.
[33]刘蜀知,任书泉.三维水力压裂裂缝中的温度场模型[J].低渗透油气田,1996,1(2)；47-50.
[34]HossainM M, RahmanM K, Rahman S S. A comp rehen2sive monograph for hydraulic fracture initiati on from devi2ated wellbores under arbitrary stress regi mes[C]. SPE54360,1999.
[35]Nishika T,Atluri S N. A si mple esti mati on method of stressintensity fact ors for thr ough2 cracks in angle2 plylaminates[J]. Engineering FractureMechanics, 1982,16 (4):23-28.
[36]Stephen,Daines R. Predicti on of fracture pressure for wildwell[J]. Journal of Petr oleum Technol ogy,1982,4:211-223.
[37]Parihar K S, S owdamini S. Stress distributi on in the neighbourhood of griffith and external cracks under generalsurface 1 oadings[J], Engineering Fracture Mechanics,1982,16 (4):72-86.