Study of a Method to Evaluate Hydraulic Fracturing near Wellbore Using Thermal Neutron Detection Based on Gd Tracer
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摘要: 水力压裂是提高非常规油气开采的重要手段，支撑剂位置及裂缝参数是评价压裂效果的重要因素.提出了以Gd作为示踪剂探测热中子来评价井周裂缝方法，将热中子双组扩散理论与数值模拟方法相结合，定义热中子变化参数WTN来指示裂缝宽度，并分析了岩性、井眼尺寸、地层孔隙度、地层水矿化度及含油饱和度对WTN的影响.模拟结果表明：随着裂缝宽度的增加，WTN先呈指数增加后趋于平缓；而地层孔隙度越大、地层水矿化度越小，WTN越大；井眼尺寸和地层含油饱和度的变化对WTN影响较小.利用蒙特卡罗方法建立了地层孔隙度、矿化度石灰岩地层压裂前后的数值计算模型，模拟研究了不同深度地层的热中子分布，得到了近远探测器热中子计数FAR、NEAR和WTN的响应曲线，最终处理裂缝参数结果与设定模型相吻合，验证了利用Gd示踪热中子探测方法可以来评价井周裂缝.Abstract: The proppant placement and fracture geometric parameters evaluation in hydraulic fractures are essential to optimize the stimulation strategy in unconventional oil and gas production. A new method adopting Gd as a tracer to detect hydraulic fracture near wellbore is proposed in this paper. Based on the numerical simulation and thermal neutron diffusion theory, the induced fracture width evaluation parameter WTN is defined. Then, the effect of lithology, porosity, borehole diameter, salinity and oil saturation to determination of fracture width is analyzed. The results indicate that WTN exponentially increases before leveling off with the increases of induced fracture width. The larger the porosity, and the smaller the formation water salinity, the smaller the WTN is. The dimension of hole and oil saturation have little effect on WTN. Monte Carlo method is employed to build formation model before and after hydrulic fracturing and thermal neutron distribution in strata of different depths is simulated. Also, the response curves of thermal neutron count NEAR, FAR and WTN are obtained. It is found that the fracture parameter results are consistent with the setting model, showing that the thermal neutron detection method based on Gd tracing can be used to evaluate the fracture of near wellbore.
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Key words:
- hydraulic fracturing /
- fracture width /
- gadolinium tracer /
- thermal neutron /
- Monte Carlo N-Particle(MCNP) /
- geophysics
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图 3 不同裂缝宽度条件下探测器热中子及WTN的响应关系
Fig. 3. Response curves of thermal neutron and WTN under different fracture width
图 4 不同孔隙度条件下热中子计数率及WTN对裂缝宽度的响应
Fig. 4. The response curves of the thermal neutron count rate and the WTN to fracture width under different porosity
图 5 不同孔隙度的WTN校正后与裂缝宽度的关系
Fig. 5. The relationship between the corrected WTN of different porosity and the fracture width
图 6 不同矿化度条件下热中子及WTN对裂缝宽度的响应
Fig. 6. The response of thermal neutron and WTN to fracture width under different salinity
图 8 不同井眼尺寸条件下热中子计数率及WTN对裂缝宽度的响应曲线
Fig. 8. The response curves of thermal neutron count rate and WTN to fracture width under different borehole size
图 9 不同地层岩性条件下热中子计数率及WTN对裂缝宽度的响应曲线
Fig. 9. The response curves of thermal neutron count rate and WTN to fracture width under different Lithology
图 10 不同裂缝宽度条件下热中子计数率及WTN对含油饱和度的响应曲线
Fig. 10. The response curves of thermal neutron count rate and WTN to oil saturation under different fracture width
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[1] Bhatia, K., Pande, K., 2016.First Application of Nonradioactive Tracer Technology in CSG Unconventional Basin in Central India:Optimization and Evaluation of Fracturing Treatment.SPE Asia Pacific Hydraulic Fracturing Conference, Beijing. https://doi.org/10.2118/181782-ms [2] Duenckel, R.J., Palisch, T.T., Han Xiaogang, et al., 2014.Environmental Stewardship:Global Applications of a Nonradioactive Method to Identify Proppant Placement and Propped-Fracture Height.SPE Production & Operations, 29(4):231-242. https://doi.org/10.2118/166251-pa [3] Espino, R.C.O., Narcizo, O.M., Gutierrez, J.V.U., et al., 2012.Mechanical Diverter in Stimulation Treatments with CT:Evaluated with Radioactive Tracers in Carbonate Reservoirs.SPE/ICoTA Coiled Tubing & Well Intervention Conference and Exhibition, The Woodlands. https://doi.org/10.2118/152943-ms [4] Han, X., Duenckel, R., Smith, H., et al., 2014.An Environmentally Friendly Method to Evaluate Gravel and Frac Packed Intervals Using a New Non-Radioactive Tracer Technology.Offshore Technology Conference, Houston. https://doi.org/10.4043/25166-ms [5] Huang, L.J., 1985.Theory of Radioactive Well Logging.Petroleum Industry Press, Beijing(in Chinese). [6] Kang, Y.S., Deng, Z., Wang, H.Y., et al., 2016.Fluid-Solid Coupling Physical Experiments and Their Implications for Fracturing Stimulations of Shale Gas Reservoirs.Earth Science, 41(8):1376-1383(in Chinese with English abstract). https://doi.org/10.3799/dqkx.2016.522 [7] Liu, J.T., Zhang, F., Gardner, R.P., et al., 2015.A Method to Evaluate Hydraulic Fracture Using Proppant Detection.Applied Radiation and Isotopes, 105:139-143. https://doi.org/10.1016/j.apradiso.2015.08.003 [8] Liu, J.T., Zhang, F., Wang, X.G., et al., 2014.Numerical Study on Determining Formation Porosity Using a Boron Capture Gamma Ray Technique and MCNP.Applied Radiation and Isotopes, 94:266-271. https://doi.org/10.1016/j.apradiso.2014.08.013 [9] Liu, Z.W., Sa, L.M., Wu, F.R., et al., 2013.Micro Seismic Monitor Technology Status for Unconventional Resource E & P and Its Future Development in CNPC.Oil Geophysical Prospecting, 48(5):843-853(in Chinese with English abstract). [10] McDaniel, R.R., Borges, J., Dakshindas, S.S., 2007.A New Environmentally Acceptable Technique for Determination of Fracture Height and Width.SPE Annual Technical Conference and Exhibition, Anaheim. https://doi.org/10.2118/109969-ms [11] McDaniel, R.R., Holmes, D.V., Borges, J., et al., 2009.Determining Propped Fracture Width from a New Tracer Technology.SPE Hydraulic Fracturing Technology Conference, Woodlands. https://doi.org/10.2118/119545-ms [12] Nie, X., Zou, C.C., Yang, Y.Q., et al., 2012.Application of Well Logging to the Evaluation of the Rock Mechanical Propertries.Chinese Journal of Engineering Geophysics, 9(4):432-437(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-GCDQ201204015.htm [13] Ortiz, A.C., Hryb, D.E., Martínez, J.R., et al., 2016.Hydraulic Fracture Height Estimation in an Unconventional Vertical Well in the Vaca Muerta Formation, Neuquen Basin, Argentina.SPE Hydraulic Fracturing Technology Conference, The Woodlands. https://doi.org/10.2118/179145-ms [14] Saldungaray, P., Duenckel, R.J., Palisch, T.T., 2014.Reducing Hydraulic Fracturing HSE Footprint through the Application of a Non-Radioactive Method for Proppant Placement and Propped Fracture Height Assessment.SPE Middle East Health, Safety, Environment & Sustainable Development Conference and Exhibition, Doha. https://doi.org/10.2118/170333-ms [15] Salman, A., Kurtoglu, B., Kazemi, H., 2014.Analysis of Chemical Tracer Flowback in Unconventional Reservoirs.SPE/CSUR Unconventional Resources Conference, Calgary. https://doi.org/10.2118/171656-ms [16] Silber, R., Martin, J., Willis, S., et al., 2003.Comparing Fracture Simulation Design to Radioactive Tracer Field Results:A Case History.SPE Eastern Regional Meeting, Pittsburgh. https://doi.org/10.2118/84842-ms [17] Torres, F., Reinoso, W., Chapman, M., et al., 2012.Traceable Proppant Eliminates Need for Radioactive Detection Material.Journal of Petroleum Technology, 64(6):33-39. https://doi.org/10.2118/0612-0033-jpt [18] Wang, C.L., Zhou, W., Li, H.B., 2014.Status and Ke Technologies of Shale Oil and Gas Exploration and Development.Journal of Oil and Gas Technology, 36(4):51-55(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-JHSX201404010.htm [19] Yi, X.M., Tang, X.P., Liang, T., et al., 2009.Prediction and Assement of Fracture Height of Hydraulic Fracturing with Logging Data.Journal of Southwest Petroleum University(Science & Technology Edition, 31(5):21-24(in Chinese with English abstract). [20] Yuan, C., Li, C.L., Zhou, C.C., et al., 2014.Numerical Simulation of Response Characteristic of Neutron Porosity Logging While Drilling.Earth Science, 39(2):1896-1902(in Chinese with English abstract). https://doi.org/10.3799/dqkx.2014.174 [21] Zhang, F., Yuan, C., Liu, J.T., et al., 2013.Numerical Simulation on Pulsed Neutron-Gamma Ray Density Logging Response in Logging while Drilling.Earth Science, 38(5):1116-1120(in Chinese with English abstract). https://doi.org/10.3799/dqkx.2013.110 [22] Zhang, L., Luo, J., Cui, G.D., et al, 2016, Mechanisms of Cold Shock during Coalbed Fracturing Assisted with Cryogenic Gases.Earth Science, 41(4):664-674(in Chinese with English abstract). https://doi.org/10.3799/dqkx.2016.055 [23] 黄隆基, 1985.放射性测井原理, 北京:石油工业出版社. [24] 康永尚, 邓泽, 王红岩, 等, 2016.流-固耦合物理模拟实验及其对页岩压裂改造的启示.地球科学, 41(8):1376-1383. https://doi.org/10.3799/dqkx.2016.522 [25] 刘振武, 撒利明, 巫芙蓉, 等, 2013.中国石油集团非常规油气微地震监测技术现状及发展方向.石油地球物理勘探, 48(5):843-853. http://d.old.wanfangdata.com.cn/Periodical/sydqwlkt201305024 [26] 聂昕, 邹长春, 杨玉卿, 等, 2012.测井技术在页岩气储层力学性质评价中的应用.工程地球物理学报, 9(4):432-437. http://d.old.wanfangdata.com.cn/Periodical/gcdqwlxb201204012 [27] 王翠丽, 周文, 李红波, 2014.页岩油气勘探开发现状及关键技术.石油天然气学报, 36(4):51-55. doi: 10.3969/j.issn.1000-9752.2014.04.010 [28] 易新民, 唐雪萍, 梁涛, 等, 2009.利用测井资料预测判断水力压裂裂缝高度.西南石油大学学报(自然科学版), 31(5):21-24. doi: 10.3863/j.issn.1674-5086.2009.05.006 [29] 袁超, 李潮流, 周灿灿, 等, 2014.随钻中子孔隙度测井响应特性数值模拟.地球科学, 39(12):1896-1902. https://doi.org/10.3799/dqkx.2014.174 [30] 张锋, 袁超, 刘军涛, 等, 2013.随钻脉冲中子——伽马密度测井响应数值模拟.地球科学, 38(5):1116-1120. https://doi.org/10.3799/dqkx.2013.110 [31] 张亮, 罗炯, 崔国栋, 等, 2016.低温气体辅助煤层气压裂中的冷冲击机理.地球科学, 41(4):664-674. https://doi.org/10.3799/dqkx.2016.055 -
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