3.5D地震勘探实例研究

Case study for 3.5-D seismic exploration

(1.CNPC 东方地球物理公司凌云研究组，河北涿州072751；2.北京旭日奥油能源技术有限公司，北京100101；3.中国石油新疆油田分公司开发研究院，新疆克拉玛依834000)

Lingyun Research Group, BGP.CNPC, Zhuozhou 072751, China

3D和随时间推移（TL）地震是油田评价与开发阶段重要的地震勘探方法。近年来，TL地震正逐步成为油藏开发和管理中的重要手段之一。但TL地震受到储层条件、开采方式、TL地震勘探过程中非重复性噪声以及一些油田在开发早期未开展基础3D地震观测等诸因素的影响，这些因素使得这一技术在陆上油田开发中的应用受到了制约。为此，提出了3.5D地震勘探方法。3.5D地震勘探方法应用油田开发中、晚期的高精度3D地震数据，结合油田开发动态信息解决油田开发中存在的问题，寻找剩余油气分布区域。通过对中国西部某油田的开发实例研究，认为：3.5D地震可以较有效地解决油田开发中的问题，发现剩余油气的分布，不但解决了一些油田早期没有3D地震或早期3D地震数据质量存在严重非重复性噪声影响的问题，同时还可降低TL地震勘探的风险，提高油田开发的经济效益。

3-D and 4-D (or time-lapse) seismic are important exploration techniques for field evaluation and development phase. Increasingly, time-lapse seismic is becoming a most popular tool for reservoir development and management. However, its application is constrained by reservoir conditions, production mechanism, non-repeatability noise in time-lapse seismic, and even the availability of basic 3-D seismic survey. This constrains the application of time-lapse seismic in onshore fields. Therefore, a 3.5-D seismic technique was proposed. The high quality 3-D seismic data obtained in the middle and later stage for reservoir development is used in the technique, combined with the production history to solve the problems in reservoir development and identify the distribution of residual hydrocarbon. The application to an onshore field in West China shows that 3.5-D seismic can effectively solve the problems in reservoir development, identify the distribution of residual hydrocarbon, and overcome the problem of the shortage of 3-D seismic or the impact of non-repeatability noise in the early stage of field. At the same time, the technique can decrease the risk of time-lapse exploration and improve the economic benefit of reservoir development.