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风城陆相稠油油藏原油黏度高,通常采取挤液预处理储层改造结合SAGD方式开采。为了理解注入液和冷凝液在油藏中的运移规律,需要掌握该油砂的亲水和润湿机理。本文选取风城油砂样品,通过X射线衍射、环境扫描电镜、接触角和核磁共振系列实验,研究处于不同压差和酸碱度环境下的样品的亲水性与润湿性。研究发现风城油砂发育疏松结构,沥青作为砂粒彼此间的胶结物存在而不呈现“油包砂”的结构形式;风城油砂倾向于亲水,饱和盐水在岩心中以水膜和孔隙水两种形式存在;增大饱和压差或饱和盐水的酸碱度均会造成水膜变厚和孔隙水体积增加。综合分析可知,风城油砂亲水且水润湿,加大注入压差可更高效地将汽液注入地层,且添加化学用剂不会损害储层的可注性。
Fengcheng continental heavy oil reservoir crude oil viscosity is high, usually take the squeeze liquid pretreatment reservoir modification combined with SAGD mining. In order to understand the migration rules of injection liquid and condensate in a reservoir, it is necessary to know the mechanism of hydrophilicity and wetting of the oil sand. In this paper, samples of windfarm oil sands were selected to study the hydrophilicity and wettability of the samples in different pressure and pH conditions by X-ray diffraction, environmental scanning electron microscopy, contact angle and nuclear magnetic resonance experiments. It is found that Fengcheng oil sands develop loose structure, and asphalt as the cement between sand particles does not show the structural form of “oil-packed sand”. Fengcheng oil sands tend to be hydrophilic and saturated saline water film And pore water exist in two forms; increasing the saturation pressure or saturated saline pH will cause the water film thickening and pore water volume increases. Comprehensive analysis shows that, Fengcheng oil sands are hydrophilic and water-wet. Increasing injection pressure can inject gas-liquid into the formation more efficiently, and adding chemical agent will not damage the reservoir’s injectability.