车排子区块火山岩蚀变层段识别方法及其对产能的影响
Identification Method of Volcanic Rock Alteration in Chepaizi Area and Its Impact on Production Capacity

在火山岩的储层评价中，蚀变作用表现为良好储层特征，但实际物性、孔隙连通性差，为非储层或差储层。因此识别火山蚀变带具有重要意义。本文以准噶尔盆地车排子地区中基性火山岩为例，通过观察电镜薄片，分析测井曲线响应特征，选取测井敏感曲线建立Rt-ΦCNL储层蚀变程度识别图版。利用中子测井、电阻率测井对数值，建立蚀变指数AL，将蚀变等级划分为轻度或未蚀变(AL < 12)、中度蚀变(12 < AL < 27)、重度蚀变(27 < AL < 80)三个等级。随火山岩蚀变程度加深，电成像测井中孔隙度分布谱由宽变窄，重度蚀变段孔隙度谱窄而不连续。基于其响应特征建立孔隙度谱指数FE和蚀变指数AL的火山岩产能图板，图版说明强蚀变作用下的火山岩会降低储层产能，对产能类型的判别与实际试油结论相符。
In the evaluation of volcanic reservoir, alteration shows good reservoir characteristics. However, the actual physical property and pore connectivity are poor, and they are non-reservoir or poor reservoir. Therefore, it is of great significance to identify the volcanic alteration zone. Taking the intermediate-basic volcanic rocks in Chepaizi area, Junggar Basin as an example, by electron microscope observation of the thin section of the cast, it was found that the logging response characteristics of alteration. The RT-ΦCNL reservoir alteration degree identification chart was established by using logging sensitive curves. Based on the neutron and resistivity logging values, the alteration index Al was established and the alteration grade was divided into three: weak or no alteration (Al < 12), moderate alteration (12 < Al < 27) and strong alteration (27 < Al < 80). With the increase of the alteration degree and clay content, electrical imaging porosity spectrum is from wide to narrow, and the porosity spectrum of heavy alteration is narrow and discontinuous. The above methods are used to identify the alteration zone and analyze the effect of alteration on productivity. The results show that the chart of alteration index Al and test production can indicate the production capacity. This study has reference significance for the identification and evaluation of volcanic alteration zones in other areas.