徐家围子地区深层火山岩气水层解释评价方法

Interpretation and evaluation for deep volcanic gas-water layers in Xujiaweizi region

大庆探区徐家围子地区深层火山岩岩性复杂,储集层类型多、厚度大、钻井取心少.以往储集层物性评价主要根据钻时、岩心实物观察与孔渗分析及测井岩性密度等资料进行,评价难且复杂.而含气性评价主要依据气测全烃含量的大小.其影响因素和各自的局限性给录井深层火山岩天然气井储集层解释评价带来难度.气水层解释评价符合率较低。针对该地区火山岩气藏储集层.在分析利用dcs指数和孔隙度反映物性.并应用气测全烃以及地层含气饱和度指教反映含气性的基础上.分别建立dcs指数-全烃和地层舍气饱和度指数-孔隙度解释评价图板。实践表明.应喟该方法效果较好.提高了深层火山岩天然气井的录井解释评价精度.可为试气井段的确定以及压裂选层提供可靠依据。

The deep volcanic lithology in Xujiaweizi region,Daqing exploration area is complex with variety of reservoir types,large thickness,less drilling coring,previous physical property evaluation was mainly based on drilling time,core observation,porosity and permeability analysis,logging lithology density and other data,evaluations were difficult and complex,while the main basis for gas evaluation was the size of total hydrocarbon content on gas logging,the influence factors and their limitations brought difficulty to interpret and evaluate mud logging reservoirs in deep volcanic natural gas wells,the interpretation and evaluation coincident rate for gas-water layers was lower.In accordance with the gas reservoirs of volcanic rock,based on analyzing and using dcs index and porosity to reflect the physical properties,and using total hydrocarbon of gas logging and formation gas saturation index to reflect gas-bearing property,interpretation and evaluation charts were established respectively between dcs index and total hydrocarbon,formation gas saturation index and porosity.Practice showed that the method is better to improve mud logging interpretation and evaluation accuracy of deep volcanic natural gas wells and can provide a reliable basis for determining the horizons of gas testing and fracturing.