对比研究纵、横波速度方位各向异性,对确定方位各向异性敏感参数非常重要.利用中国东部某盆地B区深层OVT域道集数据,开展了纵、横波速度各向异性反演,分别得到了对应的各向异性强度和方向.基于横波速度各向异性强度和方向的解释结果与研究区已知井资料揭示的裂隙信息吻合,与区内断裂关系合理,即各向异性强度大的区域附近断裂发育,各向异性方向大致平行于断裂走向;基于纵波速度求得的各向异性强度明显小于基于横波速度求得的各向异性强度,其各向异性方向偏差较大,与区内断裂关系不甚合理,即断裂附近的各向异性强度很小,各向异性方向与断裂并未大致平行或呈锐角相交.因此,横波速度对方位各向异性更敏感,反映的裂隙分布也更可靠.

随着致密气勘探开发的不断深入,断裂对气层的分布以及对储层物性的改造均起到了重要的控制作用.受随机噪声、采集脚印等多种因素的制约,地震资料信噪比低,成像品质较差,常用于识别断层的方差或相干属性的清晰度已不能满足指导微小断层组合的要求.为了解决研究区构造解释的难题,采用倾角导向滤波控制的似然属性方法提高断层识别精度,并基于似然属性体,确定随机噪声与断层的阈值,结合区域地质分析,认为似然属性值<0.3为噪声,≥0.3为断层,最后利用断裂预测结果计算裂缝密度和连通性,可以对断裂发育情况进行半定量—定量描述,能够全方位多角度地认识裂缝在平面、剖面和三维立体空间的展布特征.该方法突破了传统意义上地震解释中的断层识别方法,解决了常规相干呈现杂乱模糊响应及断层、岩相变化无法区分的问题,提高了地震解释的精度及可信度,为水平井轨迹设计及压裂方案优化提供了技术支撑.

The Linxing-Shenfu block is located in the eastern margin of Ordos basin.The Tai-2tight sandstone is the main gas productive reservoir in this block.Because the reflectance signature of gas sand is sheltered by the coal seam developed above and beneath the Tai-2formation, it is difficult to identify the gas layer using the conventional seismic reservoir prediction methods.We proposed a seismic constraint-based technology for elimination of strong coal seam reflection via well-control and matching pursuit on the basis of analyzing the strong reflection amplitude characteristics of the Linxing-Shenfu block in the eastern margin of Ordos basin and identifying its genetic mechanism.This technology extracts the reasonable matched waveform of coal seam using well-side seismic traces, then dynamically adjusts the matching wavelet control parameters with the improved matching pursuit algorithm, and eliminates strong coal seam reflection from original seismic after obtaining the reflectance signature to highlight the reflectance signature of tight sandstone.The feasibility of this method is verified through numerical modelling, synthetic seismogram and the actual seismic profile, the target sand body is highlighted through eliminating the sheltering of coal seam, and the prediction results are in good agreement with the thickness of drilled sandstone.

In Hengshanbu block on the west edge of Ordos Basin, a series of NNE thrust faults have been developed, which are roughly evenly spaced and parallel. It is shown that the faults distributed in east-west zoning on the plane, which can be divided into three sets of fault systems, including the inversion of faulted anticlinal structures in the west and flower structures in the centre, and the inversion of thrust faults in the east. In profile, many kinds of structural styles, such as anticlinal, flower structure, controlled by thrust fault, have been developed. It is concluded that fault is the main controlling factor for oil and gas accumulation by analyzing the reservoir characteristics of Liujiazhuang gas field and Shengli gas fields around Hengshanbu block. Based on the combination of different faults, two types of accumulation models, namely inversion structure and flower structure, are proposed.

It's a very important link for oil exploration and development to comply the oil and gas reservoir description and mod-eling.Due to the band limitation of seismic frequency,the vertical resolution of deterministic inversion is low,and it's very dif-ficult to identify the reservoirs with smaller thickness.Base on the practical application in oilfield A,geostatistic inversion method was carried out using stochastic modeling techniques with the high-density seismic data,integrated geological,logging and 3D seismic data effectively,we can improve the vertical resolution of predicted results greatly,and the thin layer of sand can be identify better,which can provide a reliable basis for the reservoir identification and modeling.

我国页岩气开采还处于起步阶段,为了推动我国页岩气开发,中海油页岩气科研团队研究出了一套页岩油气水平井井组地质油藏设计流程和技术方法,包括页岩平面分区、纵向定带、轨迹定向、储量估算及产量预测、风险分析等.应用该套设计流程和技术方法对中海油已并购的美国页岩油气资产区进行了页岩油气水平井井组地质油藏设计,其结果满足了生产需求,同时也体现了自主研发的特色.

When AVO analysis and inversion are applied to reservoir prediction and fluid detection, the various seismic attribute value ranges need to be defined simultaneously to effectively characterize the reservoir distribution. However, Poisson impedance (PI) attribute usually acts as an indicator of oil and gas. That means the single PI attribute can be used to realize reservoir characterization, and obviously eliminate the affection of compaction background trend. After a joint study of rock physics, PI curve calculated from logging data and seismic combined with logging, we have accomplished the reservoir prediction of an interesting zone in the Block H of the West Africa coastal basin. The following observations are obtained: (1) Reservoir prediction and fluid detection will be failed only with P-wave impedance, or S-wave impedance, or P and S wave velocity ratio, or Poisson ratio respectively. (2) The PI threshold values for different formation lithology do not change at any depth. So the affection of compaction background trend can be eliminated, and the PI attribute can be effectively used to identify lithology or hydrocarbon. The oil sands PI range is less than 1250g/cm3·m/s, and the water-saturated sands PI range is between 1250g/cm3·m/s and 1600g/cm3·m/s, but the mudstone PI range is more than 1600g/cm3·m/s. (3) The PI value keeps a negative correlation relationship with oil saturation. Using PI attribute, both the interesting exploration targets and their distribution in the Block H are defined.

利用地震叠前AVO分析和反演技术进行储层预测和流体检测时,一般需要同时确定多种属性数据体的数值范围,才能有效地刻画储层分布特征.而泊松阻抗属性(PI)可作为一种有效的油气指示器.即单独利用PI数据体就可实现储层表征,且能较好地消除明显的压实背景趋势的影响.文中通过岩石物理分析、井中泊松阻抗曲线求取、井震结合分析,对西非海岸盆地H区块进行了有利目标预测,得出以下认识:①单独利用纵波阻抗、横波阻抗、纵横波速度比和泊松比等属性参数均不能实现储层预测和流体检测；②对于任何深度段的地层,不同岩性的PI门槛值都固定不变,有效消除了地层压实背景趋势的影响,因此利用PI可以有效识别岩性和含油气性,其中含油砂岩落在PI＜1250g/cm3·m/s的区域,含水砂岩落在1250g/cm3·m/s＜ PI＜ 1600g/cm3·m/s的区域,泥岩落在PI＞ 1600g/cm3·m/s的区域；③PI值大小与含油饱和度存在较好的负相关关系.通过PI属性筛选出H区块内的有利勘探目标,进而描述了有利勘探目标的空间分布特征和范围.

Many gas wells were discovered in Z blocks,and the number of gas layer is larger in single well and the total gas is thick.In the seismic profile,the gas-bearing event features in higher thickness,dropping down and low frequency.There are many reasons for òbright spotó in this area,and the gas and gas-water layer of different saturation is strong in amplitude.Studies suggest that it is not difficult to identify the distinction between the water and gas,but the quantitative prediction of gas saturation.In this paper,based on pre-stack inversion and rock physics analysis,perturbation experiments were conducted to identify the sensitive parameter for saturation and obtained the sensitive parameter and the relationship between the density and saturation.Finally the relationship was used to examine the application effect in overseas oil and gas basins.

扩展弹性阻抗反演技术是油气勘探领域正在兴起的一项新技术,利用分角度叠加数据及横波、纵波、密度等测井资料,可以联合反演出与岩性、含油气性相关的多种弹性参数,用于综合判别储层的物性及含油气性.本文在简要论述叠前弹性波阻抗反演的基本原理及方法的基础上,给出了该方法的反演实例,指出了该方法的应用条件和关键步骤.对X地区含气砂岩的实例研究表明,扩展弹性阻抗反演对含气砂岩具有非常理想的分辨能力,能够可靠地识别含气砂岩的分布范围.

Aiming at the difficulty that any single parameter of P-wave impedance and elasticity can't be used to identify reservoirs in Qiongdongnan basin,an attribute analysis of Poisson impedance has been selected.This method integrates two attribute information of Poisson ratio and density and has a higher resolution for porous sandstones and gas-bearing sandstones.For X structure target in Qiongdongnan basin,this method was applied to analyse the space distribution of hydrocarbon zones and porous sandbodies,and the prediction results were confirmed by drilling.