巴中地区千佛崖组储层岩石物理及地震响应特征分析

发布时间：2018-03-01 20:31

本文关键词： 致密砂岩岩石物理地震响应千佛崖组巴中地区　出处：《长江大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国致密砂岩天然气资源十分丰富,其中天然气产量有近1/3产自非常规的致密砂岩储层。根据现有储量分析,5年之后常规天然气将会出现陡坡下滑的趋势,非常规致密砂岩天然气藏将是天然气勘探开发的主要对象。元坝地区中浅层共划分为西部、中部断褶带及巴中3个有利区带,须四段和珍珠冲段是元坝中部断褶带主要的含气目的层。在近期勘探中,巴中地区多口井在千佛崖组钻遇不同程度的气显示,其中元坝9井千佛崖获气2.2万方,油16.6方,表明了千佛崖组具有富集高产的特点。因此,本文针对巴中地区千佛崖组致密砂岩储层预测这一主题。结合千佛崖组储层地质特征,在统计分析测井响应特征的基础上,得出在GR背景下,选取ZpZs交会作为砂体敏感参数对,在孔隙度背景下,选取VpVp Vs交会作为储层物性敏感参数对。然后从地震数据体中提取相应的敏感属性,并结合AVO响应特征从而提高对储层和流体的有效预测精度,指导下一步储层预测的工作。所取得成果及认识如下:(1)砂岩段表现为低自然伽马、高孔隙度以及低泥质含量,高密度、较高的纵波速度和横波速度、较高的纵波阻抗和横波阻抗;泥岩段表现为高自然伽马、低孔隙度以及高泥质含量,相对低的密度、相对低的纵波速度和横波速度、相对低的纵波阻抗和横波阻抗。含气层段为砂体的一部分,与砂体的响应特征特征一致。此外,含气层段的纵横波速度比相对其他非含气层段的较低,这是含气层段表现最显著的测井响应特征。(2)岩石物理分析得出,在GR背景下,选取ZpZs交会作为砂体敏感参数对;在孔隙度背景下,选取VpVpVs交会作为储层物性敏感参数对。(3)实际井资料AVO正演模拟认为,含气层表现为第IV类AVO响应特征;差油气层表现为第II类AVO响应特征。含气饱和度、孔隙度和储层厚度的变化对AVO响应特征的影响表现出一定的规律特征:随着含气饱和度的增大,含气层顶部同相轴振幅逐渐减小;P值减小,G值增大,且Sg由0到20%过程中变化幅度较大,AVO响应在第Ⅳ类中变化;随着孔隙度的增大,含气层顶部同相轴振幅逐渐减小;P值减小,G值增大,且变化幅度逐渐减小,AVO响应在第Ⅳ类中变化;随着含气层厚度的增大,含气层顶部同相轴振幅值减小;P值先减小后增大,G值先增大后减小,AVO响应由第Ⅲ类向第Ⅳ类转化。(4)AVO异常属性分析得出,本区目的层含气性敏感属性为泊松比、流体因子、AVO强度和P*signG。(5)千佛崖组地震地质特征分析:在千一段底部同相轴出现“复波”现象,说明千一段下部纵向上岩性、物性变化较小,由下部到上部砂泥岩分布存在较大的差异性。因而砂体横向展布较广,厚度变化较快;千二段同相轴近似平行,整体上表现为平行或近平行同相轴地震相。在千二段中、上亚段同相轴振幅较强,局部出现“复波”现象,说明千二段中、上亚段横向岩性、物性变化较大。其中在千二段下亚段能识别出砂体自北东向展布,千二段中、上亚段为自北东向和东部展布;千三段同相轴近似平行,整体上表现为平行或近平行同相轴地震相。在千三段下部同相轴振幅较强,局部出现“复波”现象,说明千三段纵向、横向上岩性、物性变化较大。
[Abstract]:China's tight sandstone gas resources are very rich, the natural gas production is nearly 1/3 from non tight sandstone reservoir. According to the existing conventional reserves analysis, after 5 years of conventional natural gas will appear steep downward trend, unconventional tight sandstone gas reservoirs will be the main target of natural gas exploration and development in Guangyuan. In the shallow area is divided into West, central fault fold belt and Bazhong 3 favorable zones, shall be four and zhenzhuchong gas layer in central Guangyuan. In the near future bruchfalten main exploration wells drilled in Bazhong area, different degree of gas in Qianfoya, of which 9 wells of Guangyuan Qianfoya gas by 22 thousand party, the 16.6 party oil show, Qianfoya has the characteristics of enrichment. Therefore, this paper Qianfoya tight sandstone reservoir in Bazhong area. The theme of combining the characteristics of Qianfoya reservoir geological survey, statistical analysis Based on the response characteristics of wells, obtained in the context of GR, ZpZs is selected as the sensitive parameters of the intersection of sand body, in the porosity background, select the VpVp Vs fair as sensitive parameters of reservoir. And then extract the corresponding sensitive attribute from seismic data, and combining the AVO response characteristics so as to improve the prediction accuracy effectively on reservoir and fluid, under the guidance of a reservoir prediction work. The results obtained are as follows: (1) the sandstone section is low natural gamma, high porosity and low shale content, high density, high P-wave velocity and S-wave velocity, high impedance of P wave and S wave; mudstone performance of high natural gamma, low porosity and high clay content, relatively low density, relatively low P-wave velocity and S-wave velocity, relatively low impedance of P wave and S wave. Gas bearing section as part of the sand body, and the response characteristics of sand body The characteristics are consistent. In addition, the shear wave velocity of gas bearing interval ratio relative to other non gas zones with low, this is gas zones with the most significant performance of logging response characteristics. (2) the rock physics analysis, under the background of GR, ZpZs is selected as the sensitive parameters of the intersection of sand body; porosity in the background select the VpVpVs, fair as the sensitive parameters of reservoir (3). The actual logging data AVO simulation, gas bearing performance as a class IV AVO response characteristics; poor reservoir performance for the II class AVO response characteristics. The gas saturation, porosity and thickness of the reservoir changes influence on AVO response characteristics the law shows some characteristics: with the increase of the gas saturation of the gas bearing top event amplitude decreases gradually; the value of P decreases, G increases, and Sg from 0 to 20% in the process of large amplitude variation, AVO response in type IV changes; with the increase of porosity, containing gas top Part of the event amplitude decreases gradually; the value of P decreases, G increases, and the amplitude of AVO decreased gradually, in response to changes in type IV; with the increase of the thickness of gas bearing and gas bearing top event amplitude value decreases; the P value decreased firstly and then increased, G value increased first and then decreased, AVO should be a ring class III to IV grade. (4) AVO abnormal attribute analysis, the fluid factor to the gas sensitive properties for the Poisson's ratio, the strength of AVO and P*signG. (5) analysis of the geological characteristics of Qianfoya formation in seismic events "at the bottom of complex phenomenon, that part of the longitudinal 10001 on the lithology, physical changes smaller from the bottom to the upper sand mudstone distribution differences. So the transverse distribution of sand body is wide, the thickness changes rapidly; Senji segment phase axis approximately parallel to the overall performance of parallel or nearly parallel events in seismic phase. Senji section, section on Asia The event amplitude is strong, the emergence of local "wave" phenomenon, that Senji section, the upper submember transverse lithology, physical property change greatly. The Senji section under sub paragraph can be identified from North East trending sandbody, Senji section, section on Asia from North East and eastern section 1003 distribution; the in-phase axis approximately parallel to the overall performance of parallel or nearly parallel events in strong seismic facies. The lower section 1003 event amplitude, the emergence of local "wave" phenomenon, that section 1003 longitudinal, lateral lithology, physical property changes greatly.

【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13;P631.4

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