珠江口盆地碳酸盐岩下构造深度校正探讨
作者简介:易浩(1987—), 男, 湖北省天门市人, 硕士研究生, 主要从事地震勘探解释。E-mail: yihao2@cnooc.com.cn
收稿日期: 2017-07-19
要求修回日期: 2017-11-30
网络出版日期: 2018-07-16
基金资助
“十三五”国家科技重大专项(2016ZX05024004)
Seismic data depth correction of strata beneath the carbonate in the Pearl River Mouth Basin
Received date: 2017-07-19
Request revised date: 2017-11-30
Online published: 2018-07-16
Supported by
Major National Special Projects in 13th Five-Year (2016ZX05024004)
Copyright
易浩 , 卫哲 , 易雪菲 , 陈兆明 , 吴建耀 . 珠江口盆地碳酸盐岩下构造深度校正探讨[J]. 热带海洋学报, 2018 , 37(4) : 97 -104 . DOI: 10.11978/2017081
A pull-up seismic reflection imaging artifact is caused by the overlying high velocity layer, making the interpretation of the underlying strata inaccurate. This inaccuracy would make the oil & gas exploration difficult. A quantitative template of pull-up coefficient was set up based on the analysis of controlling factors and theoretical models. The structure underlying the high velocity layer can be restored by quantitative analysis of the amplitude of pull-up effect. The results show that the extent of pull-up was controlled by the rate and thickness of high velocity layer, and by the velocity of surrounding rocks. Moreover, the pull-up parameter had a linear relationship with the velocity of carbonate in template. On this basis, the geologic models were made, and the structure was analyzed in a test. It was indicated that this method could be more effective in imaging the structure.
Fig. 1 Distribution of carbonate in Huizhou depression of the Pearl River Mouth Basin图1 珠江口盆地惠州凹陷碳酸盐岩分布图 |
Fig. 2 The first model about thickness change of limestone (a) and forward result (b). Red represents wave peak, and blue represents wave trough in the result b图2 灰岩厚度变化模型一(a)和正演模拟结果(b)的对应关系 |
Tab. 1 Characteristic statistics about forward modeling表1 正演模型特征参量统计表 |
特征参量 | 灰岩 | 砂岩 | 泥岩 |
---|---|---|---|
速度/(m•s-1) | 4300 | 3700 | 3650 |
密度/(kg•m-3) | 2600 | 2305 | 2500 |
Fig. 3 The second model about velocity change of limestone (a) and forward results (b). Red represents wave peak, and blue represents wave trough in the result b图3 灰岩速度变化模型二(a)和正演模拟结果(b)的对应关系 |
Tab. 2 Characteristic statistics about pull-up coefficient表2 上拉系数参量统计表 |
围岩速度/(m•s-1) | 灰岩速度/(m•s-1) | 上拉系数a/(ms•m-1) |
---|---|---|
4300 | 0.105 | |
3516 | 4800 | 0.155 |
5300 | 0.195 | |
4300 | 0.08 | |
3650 | 4800 | 0.13 |
5300 | 0.17 | |
4300 | 0.07 | |
3720 | 4800 | 0.115 |
5300 | 0.155 |
Fig. 4 Intersection edition of pull-up coefficient图4 上拉系数交会量版 |
Fig. 5 Depth prediction model图5 深度预测模型 |
Fig. 6 The seismic profiles at Well_A and Well_B (PSTM)图6 A—B连井地震剖面(PSTM) |
Fig.7 The seismic profile at Well_A and Well_B (PSDM)图7 A—B连井地震剖面(PSDM) |
Tab. 3 Errors of well and seismic表3 井震误差统计表 |
井号 | 真实厚度/m | PSDM预测厚度/m | 误差 |
---|---|---|---|
A | 44 | 30 | 14 |
B | 172 | 114 | 58 |
Fig. 8 Regional well log correlation图8 区域连井对比 |
Fig. 9 Velocity distribution of limestone (a) and distribution of pull-up coefficient (b)图9 灰岩速度分布图(a)和上拉系数平面分布图(b) |
Fig. 10 Comparison of different mapping methods about L60图10 L60时间构造图(PSTM, a)、深度构造图(量版恢复法, b)和深度构造图(PSDM, c)的对比 |
Fig. 11 Residual analysis of sample parameters图11 样本参量残差分析 |
The authors have declared that no competing interests exist.
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