【摘要】：橡膠密封制品在油氣開采作業(yè)中發(fā)揮著重要作用。隨著油氣開采的發(fā)展,其工作環(huán)境越發(fā)惡劣,而橡膠材質(zhì)的工作性能與外界環(huán)境密切相關(guān)。在高溫高壓高含腐蝕性介質(zhì)的工況下,橡膠材質(zhì)會(huì)受到腐蝕損傷,導(dǎo)致橡膠密封制品工作性能下降,破壞井筒完整性,影響井下正常作業(yè)甚至引發(fā)安全問題。因此,研究橡膠材質(zhì)在井筒環(huán)境中的腐蝕損傷及適用性具有重要意義。 本文首先針對(duì)以往橡膠材質(zhì)實(shí)驗(yàn)研究未模擬井筒橡膠密封件工作環(huán)境和工作狀態(tài)的不足,以O(shè)形圈為試樣,自主設(shè)計(jì)了一種實(shí)現(xiàn)試樣承壓狀態(tài)的密封組件裝置和實(shí)現(xiàn)模擬井筒工況的高溫高壓動(dòng)態(tài)釜裝置。通過探究此實(shí)驗(yàn)方法的可行性,發(fā)現(xiàn)橡膠材質(zhì)在模擬井筒工況下服役后,外貌受損,幾何尺寸產(chǎn)生一定的變化,但是不能根據(jù)外形尺寸的變化準(zhǔn)確判斷橡膠材質(zhì)的優(yōu)劣,不建議將其作為橡膠材質(zhì)腐蝕損傷和適用性評(píng)價(jià)的主要考察指標(biāo)。而服役后,橡膠材質(zhì)力學(xué)性能下降,其中,拉伸強(qiáng)度降低,拉斷伸長率減小,硬度減小,壓縮永久變形增大。力學(xué)性能對(duì)比性強(qiáng),可靠度高,建議將其作為主要考察指標(biāo)。 而后模擬某高含CO2天然氣生產(chǎn)井井筒工況,在壓力為35MPa、溫度為140℃、CO2介質(zhì)體積分?jǐn)?shù)為5%,CH4體積分?jǐn)?shù)為95%的條件下,對(duì)氟碳橡膠、氟硅橡膠、四丙氟橡膠和氫化丁腈橡膠四種橡膠材質(zhì)的O型圈試樣進(jìn)行了高溫高壓腐蝕實(shí)驗(yàn)并對(duì)四種橡膠材質(zhì)在此工況下的適用性作出了評(píng)價(jià)。實(shí)驗(yàn)結(jié)果顯示,相比自由狀態(tài),承壓狀態(tài)下橡膠材質(zhì)的腐蝕損傷程度較小,且自由狀態(tài)下,橡膠材質(zhì)的液相腐蝕較為嚴(yán)重,而承壓狀態(tài)下,則是氣相腐蝕較為嚴(yán)重。因現(xiàn)場作業(yè)中,橡膠密封件通常處于承壓狀態(tài),建議以承壓狀態(tài)下的性能考察試驗(yàn)結(jié)果作為橡膠密封件可靠性和材質(zhì)適用性評(píng)估的主要參考依據(jù)。在此模擬工況下,氫化丁腈橡膠的適用性最優(yōu)。此外,結(jié)合EDS分析和拉伸斷口形貌分析,解釋了橡膠材質(zhì)在井筒環(huán)境中的腐蝕損傷機(jī)理和影響因素。研究發(fā)現(xiàn),四種橡膠材質(zhì)在此模擬工況下服役后,其拉伸斷口以脆性斷口為主。 最后,對(duì)四種橡膠材質(zhì)進(jìn)行了C02介質(zhì)滲透性測試。以橡膠密封組件內(nèi)堿性顯像劑溶液的pH值變化考察了在C02含量一定時(shí),四種橡膠材質(zhì)的C02滲透性隨環(huán)境溫度和壓力的變化。
[Abstract]:Rubber seal products play an important role in oil and gas exploitation. With the development of oil and gas exploitation, its working environment is more and more bad, and the working performance of rubber material is closely related to the external environment. Under the condition of high temperature and high pressure and high corrosive medium, the rubber material will be corroded, which will lead to the deterioration of the working performance of rubber sealing products, the destruction of wellbore integrity, the influence of normal operation and even the safety problems. Therefore, it is of great significance to study the corrosion damage and applicability of rubber material in wellbore environment. In this paper, first of all, in view of the shortcomings of the previous rubber material experiments, which did not simulate the working environment and working state of rubber seals in wellbore, the O-ring was taken as the sample. In this paper, a kind of sealing device is designed to realize the pressure state of the sample and a dynamic autoclave with high temperature and high pressure is designed to simulate the wellbore working condition. By exploring the feasibility of this experimental method, it is found that after the rubber material is in service under the simulated wellbore condition, the appearance is damaged and the geometric dimension changes to a certain extent, but the rubber material can not be judged accurately according to the change of the shape size. It is not recommended that it be used as the main index for evaluating the corrosion damage and applicability of rubber materials. After service, the mechanical properties of rubber decreased, including tensile strength decreased, elongation at break decreased, hardness decreased, compression permanent deformation increased. The mechanical property is relatively strong and the reliability is high. It is suggested that it should be regarded as the main inspection index. Then, under the condition that the pressure is 35 MPA, the temperature is 140 鈩，

本文編號(hào)：2235600