储层综合预测技术在太康地区上古生界的应用

Application of comprehensive reservoir prediction technology for Neopaleozoic formation in Taikang Area.

太康地区勘探目的层为古生界太原组、山西组、石盒子组和石千峰组,具有砂泥岩薄互层及横向不连续等特点。针对该地区探井少、地震资料品质较差等特点,开展了储层综合预测技术应用研究。首先进行了区域沉积相分析和基于层序地层格架的砂体对比,分析认为三角洲前缘水下分流河道砂体为性能良好的储集体,横向连续性较好的石盒子组砂岩为有效储集体。然后进行了储层地球物理特征分析、测井资料预处理和合成地震记录制作,根据储层为砂泥岩薄互层,地震属性特征不明显这一特点,确定以砂组为单位进行储层预测;通过测井资料预处理以及资料分析,确定自然伽马值小于60 API为有效砂岩;通过制作正负极性合成地震记录,确定该区的地震剖面为负极性剖面。最后,在精细构造解释的基础上,利用相对波阻抗对储层进行了宏观预测,采用绝对波阻抗与多参数测井反演相结合的方法,对储层进行了精细预测。对预测结果进行了质量控制,检验了预测结果的可信度,在此基础上,初步确定研究区石盒子组砂锅窑砂岩、田家沟砂岩连续性良好,是下一步油气勘探的重点。

The exploration targets of Taikang area are the terrestrial for- mation of Neopaleozoic,including Taiyuan,Shanxi,Shihezi and Shiqianfeng groups.The reservoir is characterized by thin sand- shale interbedding,great horizontal change,poor quality of seismic data,low exploration degree,and fewer boreholes drilled.The sedimentary facies is the underwater distributary channel of delta front with good accumulation ability.The sand body correlation based on the sequence strata framework indicates that the sand- stone of Shihezi group is a effective reservoir with good continuity horizontally.Firstly,the geophysical signatures of sandstone res- ervoir in the area were studied,and the difference in seismic attrib- ute of sandstone and mudstone analyzed,such as the difference in velocity and wave impedance.Thus,the sand set was defined as the unit to predict reservoir.In order to decrease error and ambigu- ity,carried on preprocessing to the logging data and seismic data used,the positive and negative synthetic seismogram of 13 wells in the area and the neighboring area was separately made,and the seismic profiles was identified as negative polarity.Then,after fine structure interpretation,the relative wave impedance inversion was proposed based on seismic wave impedance inversion theory.The distribution of reservoir was predicted macroscopically.The abso- lute wave impedance together with the multi-parameter logging in- version was used to eliminate the ambiguity of the prediction from one single attribute.The preliminary result shows that the sand- stone of Shihezi and Tianjiagou group is very good in continuity.So these formations are the favorable ones for further exploration.