【作者】 唐锡元；

【导师】 王晓冬； 陈德斌；

【作者基本信息】 中国地质大学（北京） ， 石油与天然气工程， 2006， 硕士

【摘要】 中原油田“三高一低”（高温、高盐、高压、低粘度）的地质特点决定了其三次采油有自身的特殊性。目前的化学驱、微生物采油技术仅能满足油藏温度小于90℃,矿化度 10×10⁴mg/L 以下的油藏,应用范围受到极大的限制,无法满足中原油田苛刻的油藏条件。此外,中原油田有三分之一以上的地质储量为渗透率小于50×10^-3 um²的低渗、特低渗透油藏,对这部分储量目前的注水工艺技术不能满足开发要求,主要依靠天然能量开发,采收率仅能达到 15～20%,开发效果极差。如何开发深层低渗、特低渗透油藏既是油田面临的一大难题,也是油田增产稳产的机遇和挑战,提高这部分储量的开发效果,对油田增产稳产具有十分重要的意义。目前中原油田约有 700 多口天然能量井和注水不受效井,覆盖地质储量 6000 多万吨,这些井采出程度很低（8～9%）,是 CO₂ 单井吞吐的选择对象,是以后稳产、上产的潜力。经过科技人员多年研究和国内权威专家评价,认为 CO₂ 吞吐、混相驱是提高中原油田采收率的主攻方向。CO₂单井吞吐由于投资少,见效快且能在一定程度上反映 CO₂ 驱对油藏的适应性,因此有必要对这项技术开展研究工作,并为以后的 CO₂驱做好技术准备。参照国内外 CO₂ 单井吞吐的选井条件,结合中原油田的油藏特点,选定文留油田不同原油物性的 4 口油井进行研究,希望通过对选定的油井进行室内实验及油藏数值模拟研究,了解对于中原油田油藏 CO₂ 单井吞吐的主要增产机理及影响增产效果的主要因素,以便更好地指导该项技术在中原油田的推广应用。通过对选定 4 口油井的油样进行室内注气膨胀试验和多级脱气试验研究,表明 CO₂单井吞吐的主要增产机理为:随着注入 CO₂ 摩尔百分数的增加,注气压力上升,地层油气油比发生明显的变化,特别是注气后溶解气油比明显上升,地层油体积膨胀明显,原油的比重、粘度明显降低,增加了原油的流动能力,对提高油井产量极为有利;通过采用 CMG 组份模型对注采方案进行优化设计,表明 CO₂注入量、注入速度、油井闷井时间、生产速度等存在一个优化值,需对方案进行优化设计,以获得最好的增产效果。更多还原

【Abstract】 Due to high temperature, high-salinity, high pressure, and low-viscosity geologiccharacteristic, the tertiary recovery technique in Zhongyun oil field has self-particularity.Now chemical flooding and MEOR technique can only be used in the reservoir, ofwhich temperature and salinity are below 90℃ and 10×104 mg/L respectively so thattheir applications are limited and can’t be adapt the Zhongyun oil field harsh condition.More than one-third of OOIP in Zhongyun oil field is in low-permeability, especiallylow-permeability reservoirs, of which permeability is less than 50× 10-3μm2. To thesereservoirs the injecting water technique doesn’t meet the production demand and thenature energy is mainly available for production so that efficiency of production is lowand the efficiency is only from 15% to 20%. How to develop the low-permeabilitydeep reservoirs is a problem to field and a chance and a challenge for increasing andstabling reserves. It is important for increasing and stabling reserves for field to enhancethe development efficiency of these reserves. At present there are 700 wells that are ofnatural energy or water injection, the total OOIP is about 60 million tons. This lowrecovery ratio, potential wells are suitable for huff-puff working. After many yearresearch and expert evaluation, carbon dioxide huff-puff and miscible flooding is thepossible way for zhongyuan oil field. With the characteristics of low invest and fasteffect, the technology shows some suitability to the reservoirs. So it is very necessary tobegin this work for future flooding.With the referral to the well choosing conditions aboard and reservoircharacteristics, four different wells in Wenliu were chosen for lab test and reservoirnumerical imitation research in order to study the production mechanism and effect ofcarbon dioxide huff-puff for future application.The gas-injection expansion tests and multiple-degas tests of crude oils showed thefollowing huff-puff mechanism ----with the increasing of the carbon dioxide mole percent, the injection pressure goes up, the oil/gas ratio changes greatly, especially thedissolved oil/gas ratio goes up greatly, the reservoir oil volume expands greatly, but thedensity and the viscosity decrease greatly, all these changes are very helpful for theproduction.The optimization of injection and recovery design resulting from the CMGcomposition model showed the optimization of the parameters of the carbon dioxideinjection amount, the injection speed, the time of shutoff, and the production speed isvital for a better production.更多还原