高温高盐底水油藏氮气泡沫压锥实验研究

发布时间：2018-02-27 17:29

本文关键词： 高温高盐底水油藏氮气泡沫压锥　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：底水油藏开发过程中的底水锥进问题一直阻碍着采收率的提高,严重时会出现暴性水淹,影响油井寿命。目前,氮气泡沫在国内外油田的压锥工作中取得了较好的效果,但大多应用于常规油藏。为进一步拓展氮气泡沫压锥的应用范围,本论文针对塔河某高温高盐底水油藏(温度为106～117℃,地层水矿化度为21.2×104mg/L),系统研究了氮气泡沫的泡沫性能、流度控制能力、在多孔介质中的稳定性以及压锥效果。本论文采用Waring Blender方法,在100℃、现场注入水的条件下,通过将非离子型起泡剂与两性离子型起泡剂复配,形成了耐温抗盐泡沫体系一——NL,在此基础上添加稳泡剂,形成了耐温抗盐强化泡沫体系——NLW。NL在110℃(NLW在100℃).注入水条件下的起泡体积分别为520mL和350mL,析液半衰期分别为271s和2464s；前者在110℃老化,后者在100℃老化,120d后两者的起泡体积分别为350mL和410mL,析液半衰期均为232s,NL较NLW拥有更好的泡沫稳定性。通过对NL性能进行系统评价发现：(1)适当提高起泡剂浓度(0.1%-0.6%),有利于增加起泡体积,延长半衰期；(2)优选出的泡沫体系具有盐增效效应,随着矿化度增加,半衰期不断延长；(3)随温度增加,泡沫体系的起泡体积呈指数型递增,半衰期呈多项式递减,泡沫综合指数呈多项式递减；(4)随压力增加,泡沫体系的起泡体积呈对数递增,半衰期呈多项式递增；(5)随原油加入量的增加,低浓度NL的起泡体积和半衰期不断下降,提高其浓度可在一定程度上增强其耐油性；(6)优选出的0.2%NL能降低原始油水界面张力,但降低幅度有限。在120℃,现场注入水,回压20MPa条件下,通过研究不同条件下耐温抗盐普通氮气泡沫的流度控制能力发现,气液比为2：1,注入速度为3.5m/d时,其流度控制能力最强,并且岩心渗透率越大,流度控制能力越强。通过研究氮气泡沫在多孔介质中的稳定性发现,随老化时间延长,氮气泡沫的稳定性逐渐下降；原油对氮气泡沫的稳定性影响较大,相同条件下老化5d,含油状态下残余阻力因子的降低幅度较无油状态下增加56.93%；高温对强化泡沫稳定性较明显,相同条件下老化5d,其残余阻力因子降低幅度较耐温抗盐泡沫增加62.03%。制备了底水油藏氮气泡沫压锥模型,并利用其对氮气泡沫的应用条件进行优化,结果表明,氮气泡沫的注入时机越早、避水高度越高,氮气泡沫压锥的效果越好；在生产井位置注入0.5PV纯泡沫段塞并焖井3d,氮气泡沫压锥的效果越好;同时在底水推进速度2.5-7.5m/d的范围内,氮气泡沫都能发挥较好的压锥效果。本文的研究为有助于深化对氮气泡沫的理论认识,为塔河油田开展氮气泡沫压锥现场试验奠定了工作基础。
[Abstract]:Bottom water coning of bottom water reservoir development process into the problem has hindered the improvement of recovery rate, emergence of sudden water flooding will be serious, affect the service life of the oil well. At present, the work pressure cone of nitrogen foam at home and abroad in the oil field has achieved good results, but most of them are used in the conventional reservoir. In order to further expand the scope of application of nitrogen foam pressure cone, aiming at Tahe a high temperature and high salinity reservoir (temperature of 106~117 degrees centigrade, water salinity is 21.2 * 104mg/L), the system of nitrogen foam foam properties, mobility, stability in porous medium and pressure cone effect.
This paper uses Waring Blender method at 100 degrees, water injection conditions, the nonionic foaming agent and zwitterionic compound foaming agent, forming temperature and salt resistant foam system -- NL, based on the effect of foam stabilizing agent, forming temperature and salt resistance enhanced foam system -- NLW.NL at 110 degrees C (NLW at 100 DEG C). Injection foaming volume water conditions were 520mL and 350mL, the half-life of 271s and 2464s condensate respectively; the former 110 degrees in aging, aging in the latter 100 DEG C, 120d foaming volume both were 350mL and 410mL, the half-life of condensate liquid is 232s, foam NL has better stability than NLW.
Through the systematic evaluation of the performance of NL found: (1) increasing concentration of foaming agent (0.1%-0.6%), to increase the foaming volume and prolong the half-life; (2) foam system optimized with salt effects, as salinity increased, the half-life extend continuously; (3) with the increase of temperature, the foaming volume of foam system was increasing exponentially, the half-life of a polynomial is the polynomial decline, bubble index decline; (4) with the increase of pressure, the foam foaming volume is a logarithmic increase, half-life of a polynomial increase; (5) with the increase of crude oil adding amount, foaming volume and half-life of low concentration of NL decreased continuously, increase the concentration of enhance the oil resistance to a certain extent; (6) the optimized 0.2%NL can reduce the original oil-water interfacial tension, but the decrease is limited.
At 120 degrees C, injection water, back pressure under the condition of 20MPa, through research under different conditions of temperature and salt resistance of ordinary nitrogen foam mobility, gas-liquid ratio is 2:1, the injection rate is 3.5m/d, the mobility control ability is the strongest, and the greater the core permeability, mobility control ability is stronger. By nitrogen study on the stability of foam in porous medium, with aging time prolonged, the stability of nitrogen foam decreased gradually; crude oil on the stability of nitrogen foam greatly influence the aging of 5D under the same conditions, reducing the low residual resistance factor of oil under the condition of less oil increased by 56.93% under the condition of high temperature; to strengthen the foam stability is obvious, the same under the condition of aging 5D, the residual resistance factor decreased compared with temperature and salt resistant foam increased 62.03%.
Preparation of nitrogen foam reservoir with bottom water coning model, and the use of nitrogen foam application conditions were optimized. The results show that the nitrogen foam injection in early stage, the height of water avoidance is higher, the better the effect of nitrogen foam pressure cone; in the production well into the 0.5PV position of pure foam slug and soak 3D, the better the effect of nitrogen foam pressure cone; at the same time promote the speed of 2.5-7.5m/d within the range of water, nitrogen foam can exert pressure cone better effect.
The research in this paper is helpful to deepen the theoretical understanding of nitrogen foam and lay a foundation for the field test of nitrogen foam cone in Tahe oilfield.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.46

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