Abstract:The strong reflection separation method based on matching pursuit algorithm has achieved good results in practical applications with different strong reflection types in recent years. However, the key algorithm parameter selection lacks a theoretical basis and standards with less research involved. Therefore, the meanings of the two key parameters of wavelet phase and separation coefficient are clarified during the strong reflection separation procedure in thin coal seams, and the parameter optimization method of strong reflection separation in thin coal seams based on matching pursuit algorithm is proposed, so as to further improve the characterization accuracy of strong reflection in thin coal seams and better carry out strong reflection separation, as well as reservoir prediction. Firstly, this paper classifies the strong reflection wavelet characteristics according to different types of strong reflection reservoirs and analyzes the phase feature of strong reflection in thin coal seams. Then, based on the reflection coefficient calculation and separation of the practical drilling well, the paper determines the energy relationship between strong and weak reflections and estimates the separation coefficient to improve the separation result of strong reflection. The application result shows that this method can accurately identify strong reflection features in thin coal seams and significantly improve separation results. It highlights the weak reflection characteristics of the reservoir and lays a solid data foundation for fine reservoir prediction.
ZHANG Junhua, LIU Zhen, LIU Bingyang, et al. Analysis and identification of reservoir characteristics of weak reflectors under strong shielding layer[J]. Special Oil & Gas Reservoirs, 2012, 19(1):23-26.张军华, 刘振, 刘炳杨, 等. 强屏蔽层下弱反射储层特征分析及识别方法[J]. 特种油气藏, 2012, 19(1):23-26.
[2]
QIN Xuefei, LI Wei. Research of identification and trimming of coal-bed interference in Daniudi gas field[J]. Journal of Jilin University(Earth science edition), 2011, 44(3):1048-1054.秦雪霏,李巍. 大牛地气田煤系地层去煤影响储层预测技术[J].吉林大学学报(地球科学版), 2011, 44(3):1048-1054.
[3]
MA Lingwei, YANG Qinyong, GU Hanming, et al. Simulation of reservoir seismic response in the northern slope of the middle Tarim Basin with random fracture-cavern media model[J]. Oil Geophysical Prospecting, 2016, 51(6):1119-1127.马灵伟, 杨勤勇, 顾汉明, 等. 基于随机缝洞介质理论模拟塔中北坡储层的地震响应[J].石油地球物理勘探, 2016, 51(6):1119-1127.
[4]
XIE Chunlin, HUANG Wei, GUAN Xiaowei, et al. Thin sand identification under strong reflection with volume-based waveform decomposition[J]. Oil Geophysical Prospecting, 2017, 52(3):516-520.谢春临, 黄伟, 关晓巍, 等. 波形分解技术在强反射背景下薄砂层识别中的应用[J]. 石油地球物理勘探, 2017, 52(3):516-520.
[5]
WANG Y H. Multichannel matching pursuit for seismic trace decomposition[J]. Geophysics, 2010, 75(4):V61-V66.
[6]
LI Haishan, YANG Wuyang, TIAN Jun, et al. Coal seam strong reflection separation with matching pursuit[J].Oil Geophysical Prospecting,2014,49(5):866-870.李海山, 杨午阳, 田军, 等. 匹配追踪煤层强反射层分离方法[J]. 石油地球物理勘探, 2014, 49(5):866-870.
[7]
HAN Zhanyi, SONG Wei, LI Jiguang, et al. Strong coal-seam reflection suppression by fast matching pursuit based on dictionary learning[J]. Oil Geophysical Prospecting, 2022, 57(5):1156-1163.韩站一, 宋炜, 李继光, 等. 利用字典学习快速匹配追踪压制煤层强反射[J]. 石油地球物理勘探, 2022, 57(5):1156-1163.
[8]
ZHANG Junhua, WANG Jing, WANG Yanguang, et al. A strong shielding removal method of reflection coefficient domain based on compressed sensing with L2 norm constraint along layer[J]. Oil Geophysical Prospecting, 2022, 57(2):405-413.张军华, 王静, 王延光, 等. 基于压缩感知的反射系数域沿层L2范数约束去强屏蔽方法[J]. 石油地球物理勘探,2022,57(2):405-413.
[9]
ZHU Bohua, XIANG Xuemei, ZHANG Weihua. Strong refection horizons separation based on matching pursuit algorithm and its application[J]. Geophysical Prospecting for Petroleum, 2016,55(2):280-287.朱博华, 向雪梅, 张卫华. 匹配追踪强反射层分离方法及应用[J]. 石油物探, 2016, 55(2):280-287.
[10]
YIN Xingyao,XU Lu,ZONG Zhaoyun, et al. Dynamic and fast matching pursuit method based on local frequency constraints[J]. Journal of China University of Petroleum (Edition of Natural Science), 2018, 42(6):59-66.印兴耀, 许璐, 宗兆云, 等. 基于局部频率约束的动态快速匹配追踪方法[J]. 中国石油大学学报(自然科学版), 2018, 42(6):59-66.
[11]
XU Lu, WU Xiaohe, ZHANG Mingzhen, et al. Strong reflection identification and separation based on the local-frequency-constrained dynamic matching pursuit[J]. Oil Geophysical Prospecting, 2019, 54(3):587-593.许璐, 吴笑荷, 张明振, 等. 基于局部频率约束的匹配追踪强反射识别与分离方法[J]. 石油地球物理勘探, 2019, 54(3):587-593.
[12]
WU Xiaohe. Description technology for unconformity trap reservoirs with strong seismic reflections:a case of the Mesozoic unconformity reservoir in Changdi area, Jiyang depression[J]. China Petroleum Exploration, 2018, 23 (4):123-130.吴笑荷. 强反射背景下不整合圈闭储层描述方法——以济阳坳陷长堤地区中生界为例[J]. 中国石油勘探, 2018, 23 (4):123-130.
[13]
LIU Jie, ZHANG Zhongtao, LIU Daoli, et al. Sediment boundary identification and fluid detection for the seismic data with strong background reflections[J]. Geophysical Prospecting for Petroleum, 2016, 55(1):142-149.刘杰, 张忠涛, 刘道理, 等. 强反射背景下沉积体边界检测及流体识别方法[J]. 石油物探, 2016, 55(1):142-149.
[14]
ZHANG Shengqiang, ZHANG Zhijun, LI Yao, et al. Adaptive strong reflection separation method based on seismic phase decomposition[J]. Oil Geophysical Prospecting, 2021, 56(6):1236-1243.张生强, 张志军, 李尧, 等. 基于地震相位分解的自适应强反射分离方法[J]. 石油地球物理勘探, 2021, 56(6):1236-1243.
[15]
MALLAT S G, ZHANG Z F. Matching pursuits with time-frequency dictionaries[J]. IEEE Transactions on Signal Processing, 1993, 41(12):3397-3415.
[16]
WANG Y H. Seismic time-frequency spectral decomposition by matching pursuit[J]. Geophysics, 2007, 72(1):V13-V20.