本文選題：注空氣 + 氧腐蝕��； 參考：《中國石油大學(xué)(華東)》2015年碩士論文

【摘要】：作為一項富有創(chuàng)造性的提高采收率新技術(shù),近年來,注空氣驅(qū)油技術(shù)在國內(nèi)外受到了越來越多的重視。但由于高壓空氣的注入,使井下管柱處于高氧分壓、高溫、有水或潮濕的環(huán)境,從而遭受嚴(yán)重的腐蝕破壞,影響了油田的正常生產(chǎn)。由現(xiàn)場施工經(jīng)驗可知,腐蝕作為注空氣/空氣泡沫提高采收率技術(shù)不可避免的問題嚴(yán)重制約著該技術(shù)的應(yīng)用與推廣。為此,通過失重法、XRD分析、EDS分析以及SEM分析等方法,對井下管柱腐蝕機理與腐蝕規(guī)律進(jìn)行了深化研究。結(jié)果表明:(1)氧腐蝕速率隨著壓力的增大而加快,即使在溶解氧濃度非常低(6mg/L)的情況下,N80、P110鋼的腐蝕速率也大于行業(yè)標(biāo)準(zhǔn)(0.076mm/a),發(fā)生嚴(yán)重腐蝕。(2)氧腐蝕速率隨溫度的升高先增加后降低,一般在83℃左右達(dá)到極值;腐蝕速率隨溶液礦化度的變化同樣呈現(xiàn)此種規(guī)律,NaCl溶液達(dá)到10000mg/L時,腐蝕速率出現(xiàn)最大值。(3)在流體流動速率增大、攪拌加劇的情況下,腐蝕速率增加。(4)根據(jù)XRD、SEM分析結(jié)果,鋼材腐蝕產(chǎn)物主要元素為Fe和O,主要成分包括γ-Fe O(OH)、β-Fe O(OH)、Fe3O4、α-Fe O(OH)等,腐蝕表面膜結(jié)構(gòu)疏松不致密,對鋼材基體的保護(hù)作用不大。通過室內(nèi)實驗對氧腐蝕防護(hù)措施有效性進(jìn)行驗證,結(jié)果表明:(1)典型注空氣工況條件下,N80、P110、1Cr、3Cr鋼材均發(fā)生嚴(yán)重腐蝕破壞,而13Cr、304、3016不銹鋼腐蝕速率小于0.076mm/a。(2)利用潤滑油脂對鋼材表面進(jìn)行處理,能夠較大減緩鋼材腐蝕,其防腐效果優(yōu)于鈍化處理。(3)pH升高可以起到降低腐蝕速率的作用。(4)緩蝕劑能有效抑制管柱材料腐蝕,實驗中1#和2#緩蝕劑復(fù)配后最高緩蝕率超過了90%。注空氣工藝過程中,井下管柱面臨著復(fù)雜、惡劣的腐蝕工況環(huán)境,遭受著嚴(yán)重的腐蝕破壞。實驗研究發(fā)現(xiàn),單一的防腐措施很難將腐蝕速率控制在行業(yè)標(biāo)準(zhǔn)內(nèi),因此需要多元措施聯(lián)用,形成系統(tǒng)的防腐方案。
[Abstract]:As a creative new technology to improve oil recovery, air injection flooding technology has been paid more and more attention in recent years. However, due to the injection of high pressure air, the downhole pipe string is in a high oxygen partial pressure, high temperature, water or wet environment, thus suffered serious corrosion damage, affecting the normal production of oil fields. It can be seen from site construction experience that corrosion as an inevitable problem of air / air foam enhanced recovery technology seriously restricts the application and popularization of this technology. Therefore, the corrosion mechanism and corrosion law of underground pipe string were studied by means of weightlessness method, XRD analysis, EDS analysis and SEM analysis. The results show that: (1) the oxygen corrosion rate increases with the increase of pressure, even when the dissolved oxygen concentration is very low (6mg / L), the corrosion rate of N80P110 steel is higher than that of industry standard (0.076mm/a). (2) the oxygen corrosion rate increases first and then decreases with the increase of temperature. The corrosion rate of NaCl solution reaches the maximum value when the salinity of NaCl solution reaches 10000mg / L. (3) when the fluid flow rate increases and the stirring intensifies, the corrosion rate reaches the maximum value at about 83 鈩，

本文編號：2099234