川南深层页岩气体积压裂工艺技术

doi:10.13809/j.cnki.cn32-1825/te.2021.01.014

摘要/Abstract

摘要：

威荣深层页岩埋深大（3 500~4 200 m）、地应力高、地应力差异大（7~17 MPa）、储层脆性低（＜0.5）、天然裂缝不发育,压裂改造面临施工压力高、压力窗口窄、敏感砂比低、加砂难度大。大型物模实验表明,威荣页岩压裂裂缝形态以主缝+分支缝为主,裂缝复杂程度低,压裂易形成双翼缝。在地质工程一体化的基础上,结合地质甜点优化分段分簇,进一步细分切割地层。通过支撑剂运移规律研究,优化了三级粒径支撑剂铺置方式和注入时机,提高了加砂强度。通过复合暂堵转向压裂工艺提高了裂缝横向复杂程度,并通过缝内暂堵、优化施工排量和液体黏度,提高缝内净压力及裂缝复杂程度,从而提高压裂改造体积和控制储量。研究成果在威荣气田得到了成功应用,加砂强度提高至1.95 t/m,压后单井平均无阻流量为38.5×10⁴ m³/d,单井EUR（估算最终可采储量）为0.9×10⁸ m³,改造效果较前期显著提高。压后评估可知,压裂效果与加砂强度成正相关关系。因此,深层页岩气如何提高加砂强度、控制用液强度,是经济有效压裂的关键。

关键词: 深层页岩气, 密切割, 压裂, 加砂强度, 暂堵转向, 压裂改造体积

Abstract:

Due to the deep buried depth（3 500~4 200 m）, high ground stress, high ground stress discrepancy（7 to 17 MPa）, low reservoir brittle（< 0.5） and the undeveloped natural fracture, the hydraulic fracture of Weirong deep shale gas face the problems of high fracturing construction pressure, narrower pressure window, low sensitive sand concentration, high fracturing difficulty. Large-scale physical model experiments show that the morphology of Weirong shale fractures are composed of main fracture and branch fracture, within low fracture complexity and forming bedding seam more easily. On the basis of geology-engineering integration, the stratigraphic segmentation and clustering are optimized in combination with geological sweet spot. Through the study of the proppant transport, the placement mode and injection timing of the three-grade particle size proppant have been optimized, which increase the sand loading. The transverse complexity of fractures is improved by the combined temporary plugging steering fracturing technology. The net pressure and complexity of fractures are improved by the temporary plugging in the fractures and the optimization of construction discharge and liquid viscosity, thereby improving the fracturing volume and control reserves. The research results have been successfully applied in Weirong Gas Field. The sand loading has been increased to 1.95 t/m, the average open flow per well is 38.5×10⁴ m³/d, and the single well EUR is 90×10⁸ m³. All those shows a significantly improvement compared with the previous stage. Post-pressure evaluation shows that the fracturing effect is positively correlated with the sand adding strength. Therefore, how to improve the sand adding strength and control the strength of the liquid used in deep shale gas is the key to economic and effective fracturing.

Key words: deep shale gas, close-cut, fracturing, intensity of sand, temporary plugging and steering, fracturing volume

中图分类号:

王兴文,林永茂,缪尉杰. 川南深层页岩气体积压裂工艺技术[J]. 油气藏评价与开发, 2021, 11(1): 102-108.

Wang Xingwen,Lin Yongmao,Miao Weijie. Volume fracturing technology of deep shale gas in southern Sichuan[J]. Reservoir Evaluation and Development, 2021, 11(1): 102-108.

图/表 15

表1

表2

图1

图2

表3

图3

图4

图5

图6

图7

图8

图9

表4

图10

图11

参考文献 22

[1]	贾承造, 郑民, 张永峰. 中国非常规油气资源与勘探开发前景[J]. 石油勘探与开发, 2012,39(2):129-136.
	Jia Chengzao, Zheng Min, Zhang Yongfeng. Unconventional hydrocarbon resources in China and the prospect of exploration and development[J]. Petroleum Exploration and Development, 2012,39(2):129-136.
[2]	Li Y, Zhou D H, Wang W H, et al. Development of unconventional gas and technologies adopted in China[J]. Energy Geoscience, 2020,1(1-2):55-68. doi: 10.1016/j.engeos.2020.04.004
[3]	马新华, 谢军, 雍锐, 等. 四川盆地南部龙马溪组页岩气储集层地质特征及高产控制因素[J]. 石油勘探与开发, 2020,47(5):841-855.
	Ma Xinhua, Xie Jun, Yong Rui, et al. Geological characteristics and high production control factors of shale gas reservoirs in Silurian Longmaxi Foramation, southern Sichuan Basin, SW China[J]. Petroleum Exploration and Development, 2020,47(5):841-855.
[4]	郭彤楼, 张汉荣. 四川盆地焦石坝页岩气田形成与富集高产模式[J]. 石油勘探与开发, 2014,41(1):28-36.
	Guo Tonglou, Zhang Hanrong. Formation and enrichment mode of Jiaoshiba shale gas field, Sichuan Basin[J]. Petroleum Exploration and Development, 2014,41(1):28-36.
[5]	郭旭升, 胡东风, 李宇平, 等. 涪陵页岩气田富集高产主控地质因素[J]. 石油勘探与开发, 2017,44(4):481-491.
	Guo Xusheng, Hu Dongfeng, Li Yuping, et al. Geological factors controlling shale gas enrichment and high production in Fuling shale gas field[J]. Petroleum Exploration and Development, 2017,44(4):481-491.
[6]	刘土光, 张涛. 弹塑性力学基础理论[M]. 武汉: 华中科技大学出版社, 2008.
	Liu Tuguang, Zhang Tao. Basic theory of elasticity and plasticity[M]. Wuhan: Huazhong University of Science and Technology Press, 2008.
[7]	赵金洲, 李勇明, 王松, 等. 天然裂缝影响下的复杂压裂裂缝网络模拟[J]. 天然气工业, 2014,34(1):68-73.
	Zhao Jinzhou, Li Yongming, Wang Song, et al. Simulation of a complex fracture network influenced by natural fractures[J]. Natural Gas Industry, 2014,34(1):68-73.
[8]	张士诚, 牟松茹, 崔勇. 页岩气压裂数值模型分析[J]. 天然气工业, 2011,31(12):81-84. doi: 10.3787/j.issn.1000-0976.2011.12.014
	Zhang Shicheng, Mou Songru, Cui Yong. Numerical simulation models with hydraulic fracturing in shale gas reservoirs[J]. Natural Gas Industry, 2011,31(12):81-84. doi: 10.3787/j.issn.1000-0976.2011.12.014
[9]	任龙, 苏玉亮, 徐晨, 等. 非常规储层体积压裂水平井产能预测方法研究进展[C]// 2015油气田勘探与开发国际会议论文集. 西安:西安石油大学, 2015.
	Ren Long, Su Yuliang, Xu Chen, et al. Advances in the method of production performance prediction of SRV-fractured horizontal wells in unconventional reservoirs[C]// paper presented at the 2015 International Field Exploration and Development Conference. Xi’an: Xi’an Shiyou University, 2015.
[10]	王雷, 王琦. 页岩气储层水力压裂复杂裂缝导流能力实验研究[J]. 西安石油大学学报(自然科学版), 2017,32(3):73-77.
	Wang Lei, Wang Qi. Experimental research on seepage capacity of complex fracture in shale gas reservoir after hydraulic fracturing[J]. Journal of Xi’an Shiyou University(Natural Science Edition), 2017,32(3):73-77.
[11]	Zhao Z H, Wu K D, Fan Y, et al. An optimization model for conductivity of hydraulic fracture networks in the Longmaxi shale, Sichuan basin, Southwest China[J]. Energy Geoscience, 2020,1(1-2):47-54. doi: 10.1016/j.engeos.2020.05.001
[12]	Niandou H, Shao J F, Henry J P, et al. Laboratory investigation of the mechanical behaviour of tournemire shale[C]. International Journal of Rock Mechanics and Mining Sciences, 1997,34(1):3-16.
[13]	李庆辉, 陈勉, 金衍. 含气页岩破坏模式及力学特性的实验研究[J]. 岩石力学与工程学报, 2012,31(S2):3763-3771.
	Li Qinghui, Chen Mian, Jin Yan. Experimental research on failure modes and mechanical behaviors of gas-bearing shale[J]. Chinese Journal of Rock Mechanics and Engineering, 2012,31(S2):3763-3771.
[14]	孟陆波, 李天斌, 徐进, 等. 高温作用下围压对页岩力学特性影响的实验研究[J]. 煤炭学报, 2012,37(11):1829-1833.
	Meng Lubo, Li Tianbin, Xu Jin, et al. Experimental study on influence of confining pressure on shale mechanical properties under high temperature condition[J]. Journal of China Coal Society, 2012,37(11):1829-1833.
[15]	Taleghani A D, Olson J E. Analysis of multistranded hydraulic fracture propagation: an improved model for the interaction between induced and natural fractures[C]// paper SPE-124884-MS presented at the SPE Annual Technical Conference and Exhibition, October 4-7, 2009, New Orleans, Louisiana, USA.
[16]	Jeffrey R G, Zhang X, Thiercelin M J. Hydraulic fracture offsetting in naturally fractures reservoirs: quantifying a long-recognized process[C]// paper SPE-119351-MS presented at the SPE Hydraulic Fracturing Technology Conference, January 19-21, 2009, The Woodlands, Texas, USA.
[17]	李勇明, 郭建春, 赵金洲, 等. 裂缝性气藏压裂液滤失模型的研究及应用[J]. 石油勘探与开发, 2004,31(5):120-122.
	Li Yongming, Guo Jianchun, Zhao Jinzhou, et al. New model for fracturing fluid leak-off in naturally fractured gas fields and its application[J]. Petroleum Exploration and Development, 2004,31(5):120-122.
[18]	唐川. 页岩气藏水平井产量递减预测研究[D]. 成都:西南石油大学, 2013.
	Tang Chuan. The production decline prediction research of the horizontal well in shale reservoirs[D]. Chengdu: Southwest Petroleum University, 2013.
[19]	Zhou W T, Banerjee R, Poe B, et al. Semi-analytical production simulation of complex hydraulic fracture net-works[J]. SPE Journal, 2014,19(1):6-18.
[20]	王星皓. 泥页岩储层可压性研究[D]. 成都:西南石油大学, 2012.
	Wang Xinghao. Research on fracability of mud-shale reservoir[D]. Chengdu: Southwest Petroleum University, 2012.
[21]	袁俊亮, 邓金根, 张定宇, 等. 页岩气储层可压裂性评价技术[J]. 石油学报, 2013,34(3):523-527.
	Yuan Junliang, Deng Jingen, Zhang Dingyu, et al. Fracability evaluation of shale-gas reservoirs[J]. Acta Petrolei Sinica, 2013,34(3):523-527.
[22]	李勇明, 李莲明, 郭建春, 等. 二次加砂压裂理论模型及应用[J]. 新疆石油地质, 2010,31(2):190-193.
	Li Yongming, Li Lianming, Guo Jianchun, et al. Theoretical model and application of secondary sand fracturing[J]. Xinjiang Petroleum Geology, 2010,31(2):190-193.

区块	深度（m）	优质页岩厚度（m）	孔隙度（%）	TOC（有机碳含量）（%）	含气性（m³/t）	地层压力系数
威远	3 500~4200	27.5	4.0	2.2~4.0	3.3~6.4	1.96
永川	3 800~4 100	30.0	5.3	2.8~5.5	6.7	1.70
丁山	4 200~4 500	23.7~30.5	5.8	3.6	4.4	1.40~1.55
涪陵深层	3 900~4 200	49.5	3.1	2.8	4.5	1.38
涪陵中深层	2 200~2 400	38.0	4.2~6.4	1.9~2.2	2.0~6.0	1.20~1.55

井名	杨氏模量（GPa）	泊松比	脆性指数（%）	垂向应力（MPa）	最大水平主应力（MPa）	最小水平主应力（MPa）	水平地应力差异系数	水平应力差（MPa）
威荣	21.7~33.8	0.237	38~46	86.0~97.7	87.7~112.0	84.0~101.0	0.080~0.250	7.00~17.30
永川	20.2~31.4	0.228	40~50	95.1~105.5	99.2~113.6	88.1~101.0	0.110~0.160	11.10~15.80
丁山	32.32	0.200	48~55				0.125	11.70~24.00
涪陵外围	27.3~37.0	0.200~0.220	52~55	95.5~99.3	87.0~94.9	79.6~86.5	0.140	7.40~8.37
涪陵中深层	38.37	0.190~0.200	62	51.9	54.2	49.0	0.110	5.20
Woodford	34	0.180	55~75				0.075	2.00~4.00
Haynesville		0.270					0.048	3.00~5.00

井号	垂深（m）	施工压力（MPa）	井口停泵压力（MPa）	综合砂液比（%）
永页1HF	3 900~4 000	72.0~91.0	62.8~67.5	3.82
永页2HF	4 000~4 100	79.0~84.0	69.3~74.4	5.18
永页3-1HF	4 000~4 100	70.0~94.7	67.2~70.0	2.50
威页1HF	3 500~3 600	76.0~95.0	56.0~66.2	3.37

工艺	井号	簇数	横向覆盖率（%）	加砂强度（t/m）	综合砂液比（%）	无阻流量（10⁴m³/d）	预测EUR（10⁸m³）
前期	WY1HF	42	90.8	1.20	2.6	22.0	0.40
	WY23-1HF	45	91.8	1.50	3.0	38.0	0.66
	WY29-1HF	47	87.6	1.20	2.5	28.0	0.70
	WY35-1HF	35	88.4	0.90	2.8	18.0	0.54
	WY9-1HF	44	72.3	0.90	3.1	23.0	0.60
	WY11-1HF	39	67.3	0.75	2.1	15.0	0.40
	平均	42	83.0	1.05	2.7	24.0	0.55
后期	WY23-2HF	116	96.6	1.95	4.1	33.0	0.81
	WY23-4HF	108	94.8	1.95	4.1	38.0	0.90
	WY23-5HF	116	93.8	1.80	3.8	30.0	0.85
	WY23-6HF	115	97.2	1.80	3.8	33.0	0.80
	WY43-4HF	104	97.8	2.40	4.0	54.7	1.13
	WY43-5HF	98	98.2	1.95	3.5	42.5	0.93
	平均	110	96.4	1.95	3.9	38.5	0.90