本文選題：空氣驅　切入點：泡沫改善空氣驅　出處：《成都理工大學》2015年碩士論文

【摘要】：吐哈油田溫西三油藏屬于低孔、中-低滲儲層,原始地層壓力23.78MPa,地層溫度76℃,地層水礦化度20000mg/L以上,層間及平面非均質性嚴重[1]。油田進入高含水期后,井網(wǎng)及層系適應性逐步變差,自然遞減增大[2];此外,吸水能力及注入能力下降,開發(fā)效果逐漸變差,采收率不高,開發(fā)形勢嚴峻。目前,溫西三先導試驗區(qū)累積注水量109.12×104m3,累積產(chǎn)液量32.31×104t,累積產(chǎn)油量20.86×104t,剩余油量59.6×104t,綜合含水率50%,標定采收率32%,而采出程度低,僅為25.93%�？梢�,仍然有70%以上的原油殘留于地下。因此,大幅度提高溫西三油藏的采收率,具有重要的生產(chǎn)實際意義�？諝怛屘岣卟墒章始夹g,其優(yōu)勢不僅在于空氣的可注性高,還可以作為驅油介質。此外,在油藏溫度及壓力條件下,空氣中的氧氣與原油中的某些組分發(fā)生氧化反應,釋放大量熱量,大幅度降低原油粘度,進而改善水油流度比[3];氧化反應過程產(chǎn)生的大量煙道氣,擴大了空氣在油層中的波及效率,因而提高了原油的采收率[4]。然而,由于低滲油層中的嚴重非均質性,包括平面及縱向的非均質性嚴重,注空氣時,將產(chǎn)生氣竄,使得空氣驅油的效率降低。因此本文還重點開展了泡沫改善的空氣驅油效果研究。本文將溫西三區(qū)部分井組作為先導試驗區(qū),室內開展了空氣驅提高采收率實驗研究。給出了影響空氣驅提高采收率的因素;采用具有理想封堵效果的泡沫,研究了不同發(fā)泡液段塞大小改善空氣驅油效果及優(yōu)化了發(fā)泡液與空氣交替注入頻率對提高采收率的影響[5];最后,通過數(shù)值模擬室內研究結果,預測了泡沫改善空氣提高采收率效果。實驗結果表明,空氣驅較水驅能夠有效降低注入壓力,可解決注水開發(fā)注入困難的問題�？諝庾⑷攵稳麨�0.3PV時,提高采收率為6.25%,注入壓力較水驅降低0.03MPa;滲透率級差對空氣驅提高采收率的影響較大,級差越大,最終提高采收率幅度越低,且當滲透率級差大到一定程度后,即使采用空氣泡沫進行封堵,也不可能有效防止氣竄。當滲透率級差由1.3:1增大至15.7:1時,提高采收率值降低6.66個百分點。此外,室內試驗還發(fā)現(xiàn),在雙管驅替的過程中,相較于低滲層,空氣較多地進入了高滲層中。可見,未采用泡沫調剖及防竄技術時,空氣驅增采的原油主要來自于高滲層,低滲層的吸氣能力較低,油層波及效率較低,其驅油效果亦相對較低。隨著滲透率級差的增大,低滲層的含水率降低幅度通常比高滲層的含水率降低幅度大。說明低滲層的累積產(chǎn)液量隨著級差的增大而降低;相應地,高滲層的累積產(chǎn)液量增大[6]。這表明隨著非均質性嚴重程度的增大,由于氣體流動性較強,高滲層中由于嚴重不利的流度比發(fā)生了嚴重的水竄及氣竄,導致低滲層中的吸氣量減小甚至不吸氣,影響了驅油效果[7]。泡沫改善空氣驅能夠較空氣驅明顯提高驅油效率。起泡劑在高滲層運移過程中,盡管有大量氣泡破滅,同時在孔隙介質中滲流時,也有大量氣泡生成,由于有較高的視粘度及有效滲流粘度,能夠有效封堵高滲層,降低高、低滲層的吸氣及吸水剖面,甚至啟動低滲層,擴大氣驅時氣體在地層中的波及體積,從而大幅度提高采收率[8]。結果表明,起泡液段塞越大,驅油效果越好,采收率越高。當起泡液段塞大小為0.04PV,空氣段塞大小為0.3PV時,泡沫改善空氣驅提高采收率幅度為12.10%,較空氣驅0.3PV的6.25%提高5.85個百分點�？諝�/起泡液交替注入,可進一步提高或改善空氣驅的驅油效果[9]。結果表明,隨著交替頻率增大,泡沫改善空氣驅提高采收率的幅度也增大。當交替次數(shù)為8次時,提高采收率為15.33%。分析起來,主要原因是由于起泡液與空氣的多次交替注入,空氣與起泡液可以充分接觸,有利于泡沫的生成[10]。此外,由于起泡液與空氣總量一定,隨著交替次數(shù)的增加,空氣段塞與起泡液段塞在交替注入時相對減小,使得起泡液在孔隙中的發(fā)泡量增大,同時封堵大孔道、大孔隙,有效減少了氣竄的發(fā)生,較空氣驅過程改善了吸氣剖面,充分啟動了低滲層,使得低滲層的增油量較高滲層明顯變大,提高了采收率[11]。數(shù)值模擬研究結果表明,空氣段塞為0.25PV,起泡液段塞為0.05PV,交替次數(shù)為12次且注入速度與水驅相同(即160m3/d)時,先導試驗區(qū)提高的采收率12.29%、空氣增油量為68.11t/105m3,累積產(chǎn)氣1.06×107m3,比氣驅減少83.36%。
[Abstract]:Tuha oilfield reservoir belongs to the low temperature three hole in low permeability reservoir, the original formation pressure of 23.78MPa, the formation temperature of 76 DEG C above 20000mg/L, the salinity of formation water, interlayer and plane heterogeneity of [1]. oilfield in high water cut stage, wells and strata adaptability gradually becomes poor, the natural decrease of [2] increased; in addition water absorption capacity decreased, and the injection capability, development effect became worse, the recovery rate is not high, the development of the situation is grim. At present, the temperature three pilot test area of cumulative water injection of 109.12 * 104m3, 32.31 * 104t cumulative liquid production, cumulative production of 20.86 * 104t, the remaining oil quantity is 59.6 * 104t, comprehensive water content of 50% calibration, recovery 32%, and low recovery degree, only 25.93%. shows that there are still more than 70% of the crude oil remained underground. Therefore, greatly improve the recovery temperature three reservoir, has significance for practical production. Recovery technology to improve air drive, not only its advantages In the air can be injected high, also can be used as oil displacement medium. In addition, the reservoir temperature and pressure conditions, the oxygen in the air and oil in some components of the oxidation reaction occurs, releasing large amounts of heat, reduce the viscosity of crude oil greatly, and improve the water oil mobility ratio [3]; produce oxidation number the flue gas, expanding the sweep efficiency of air in the reservoir, thus improving the oil recovery rate of [4]., however, due to the low permeability reservoirs are in serious heterogeneity, including plane and vertical heterogeneity of air injection, the gas channeling, reduce the efficiency of the air displacement. So this paper studies the effect of oil also focus on the improvement of air foam flooding. The well group temperature three district as a pilot area, carried out indoor air injection experiments on EOR is given. The effect of air flooding to improve oil recovery factor; recovery With the ideal sealing effect of different foam, foaming liquid slug size improve flooding effect and optimization of air foam liquid and air injection alternately to improve [5] influence recovery frequency; finally, through numerical simulation, the results of laboratory studies, prediction of foam to improve air EOR effect. The experimental results show that the air. Compared with water flooding can reduce the injection pressure, injection water injection development can solve the difficult problem. The air injection slug of 0.3PV, improve the recovery rate of 6.25%, lower than the water flooding pressure 0.03MPa injection; permeability of air flooding improve recovery is larger, the greater the difference, and ultimately improve the oil recovery rate is low and, when the permeability ratio reaches to a certain degree, even if the use of air foam sealing, could not effectively prevent gas channeling. When the permeability ratio increased from 1.3:1 to 15.7:1, high recovery value A decrease of 6.66 percentage points. In addition, the indoor tests also found that, in the process for the double drive, compared to the low permeability layer, more air into the high permeability layer. Obviously, the foam profile control and anti channeling technology, air flooding enhanced oil recovery of crude oil mainly from the high permeability layer, low permeability and inspiratory capacity the lower layer, reservoir sweep efficiency is low, the flooding effect is also relatively low. With the increase of permeability, the water content decreased rate is usually higher than the rate of reduction of water in high permeability layer in low permeability layer. It shows the cumulative liquid production with differential increases reduced correspondingly low permeability; the cumulative, high permeability layer liquid yield increased [6]. this shows that with increasing heterogeneity in the severity of gas due to strong liquidity, high mobility layer due to serious adverse than serious water channeling and channeling, resulting in reduced intake layer do not inhale low permeability. Rang the oil displacement effect of [7]. foam flooding can improve air air injection significantly improve oil displacement efficiency. Agent in high permeability layer during migration of foaming, despite the large number of bubble burst, and seepage in porous medium, there are a lot of bubble formation, the apparent viscosity and viscosity of high effective flow, can effectively block high to reduce the high layer, low permeability layer and suction profile, even starting in low permeability reservoir, gas drive sweep volume expansion of gas in strata, and thus greatly improve the recovery rate of [8].. The results show that the foaming liquid slug flooding is bigger, better, the recovery rate is high. When the foaming liquid slug the size of 0.04PV, the air slug size is 0.3PV, the improvement of air foam flooding to improve oil recovery rate of 12.10%, compared with the air injection 0.3PV 6.25% increased by 5.85 percentage points. The air / foam alternative injection, can further improve the efficiency of oil displacement or improve air flooding Results [9]. results showed that with the alternating frequency increases, improve the air foam flooding to improve oil recovery rate increases. When the time is 8 times the turn, improve the recovery rate of up to 15.33%., the main reason is because the foaming liquid and air repeatedly alternating injection, air and foaming liquid can be fully contacted, beneficial to the formation of [10]. foam in addition, the foaming liquid and air amount, with the increase of the number of alternate, air plug and bubbly liquid slug in alternating injection is relatively reduced, increasing the amount of foaming foaming liquid in the pores, large pores and large pores, blocking, and effectively reduce the occurrence of gas channeling, improve the suction section is the air drive process, fully launched the low permeability layer, the oil layer quantity of higher layer was significantly larger in low permeability, improve the recovery rate of [11]. simulation results show that the air slug 0.25PV, foaming liquid slug 0.05P V, the number of alternation times is 12 times and the injection rate is the same as that of the water flooding (i.e. 160m3/d). The pilot test area improves the recovery factor 12.29%, the air oil increment is 68.11t/105m3, the cumulative gas production is 1.06 x 107m3, which is less than the gas drive 83.36%..

【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TE357.46

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相關期刊論文 前3條

1 蔣有偉;張義堂;劉尚奇;關文龍;陳亞平;劉雙卯;;低滲透油藏注空氣開發(fā)驅油機理[J];石油勘探與開發(fā);2010年04期

2 賈虎;趙金洲;楊懷軍;李sパ，

本文編號：1683484