本文選題：硬脆性泥頁巖 + 腐蝕　； 參考：《西南石油大學(xué)》2017年碩士論文

【摘要】：鉆遇硬脆性泥頁巖時(shí),因地層中普遍存在微納米裂縫,鉆井液及其濾液會(huì)沿著裂縫侵入地層深部,導(dǎo)致井壁失穩(wěn)。針對(duì)現(xiàn)有評(píng)價(jià)鉆井液封堵能力的裂縫寬度下限在10μm左右,明顯大于硬脆性泥頁巖中的微裂縫寬度而導(dǎo)致封堵評(píng)價(jià)手段與實(shí)際情況不能較好吻合的問題,本文選擇石英作為制備模擬裂縫的基質(zhì)材料,在半圓柱型基質(zhì)材料的拼接平面利用化學(xué)腐蝕和化學(xué)鍍膜方法,開展微納米裂縫模擬研究。裂縫寬度的表征方法是制備微納米級(jí)裂縫的基礎(chǔ),本文首先開展了裂縫寬度表征方法的研究。對(duì)采用化學(xué)腐蝕法制備的裂縫寬度,采用滲透率法、電阻值法和環(huán)境掃描電子顯微鏡觀測(cè)法進(jìn)行表征;對(duì)采用化學(xué)鍍膜法制備的裂縫寬度,采用滲透率法和環(huán)境掃描電子顯微鏡觀測(cè)法進(jìn)行表征。滲透率法和環(huán)境掃描電子顯微鏡觀測(cè)法測(cè)量裂縫寬度數(shù)值的相對(duì)標(biāo)準(zhǔn)偏差均很小,證明方法重現(xiàn)性良好。采用滲透率法研究初始裂縫的應(yīng)力敏感性,得出石英巖心裂縫的應(yīng)力敏感損害程度很弱,在經(jīng)過加、卸壓處理后,應(yīng)力變化對(duì)裂縫寬度的影響很小。采用滲透率法、環(huán)境掃描電子顯微鏡法、電阻率法對(duì)影響化學(xué)腐蝕法制備縫寬的時(shí)間、溫度、酸液比例等因素進(jìn)行單因素分析和正交試驗(yàn),結(jié)果表明:隨著溫度升高,反應(yīng)時(shí)間增大,HF濃度增大,制造出的裂縫寬度變大。在正交實(shí)驗(yàn)設(shè)計(jì)水平下得到最小縫寬的制備條件為:溫度20℃、5wt%HF:5%H_2SO_4=1:2、反應(yīng)時(shí)間20min,滲透率法表征的縫寬為1.317μm,掃描電鏡表征的縫寬為1.625μm。采用滲透率法和環(huán)境掃描電子顯微鏡法對(duì)影響化學(xué)鍍膜法制備裂縫寬度的鍍膜配方及鍍膜條件等因素進(jìn)行了探索,正交實(shí)驗(yàn)設(shè)計(jì)水平下得到的制備最小裂縫的配方和條件是:主鹽溶液:4g/LAgNO_3、10g/LNaOH,還原液:6g/L葡萄糖,2g/L酒石酸鉀鈉,反應(yīng)時(shí)間10min,滲透率法測(cè)得的縫寬為0.779μm,用掃描電鏡表征的縫寬為0.792μm。利用所制備的裂縫開展了封堵模擬實(shí)驗(yàn)的可行性探索。
[Abstract]:When drilling hard and brittle shale, the drilling fluid and its filtrate will invade the deep part of the formation along the fracture, which will lead to the instability of the wellbore because of the widespread existence of micro and nano fractures in the formation. In view of the fact that the lower limit of fracture width for evaluating the plugging ability of drilling fluid is about 10 渭 m, which is obviously larger than the microfracture width in hard-brittle shale, the sealing evaluation method does not agree well with the actual situation. In this paper, quartz is chosen as the matrix material to simulate the crack. The chemical corrosion and electroless plating methods are used to simulate the crack in the splicing plane of semi-cylindrical matrix. The characterization method of crack width is the basis of preparing micro-and nano-scale cracks. In this paper, the characterization method of crack width is first studied. The crack width prepared by chemical corrosion method is characterized by permeability method, resistance value method and environmental scanning electron microscope. Permeability method and environmental scanning electron microscope (ESEM) were used to characterize the properties. The relative standard deviation of fracture width measured by permeability method and environmental scanning electron microscope method is very small, which proves that the method has good reproducibility. The stress sensitivity of the initial fracture is studied by permeability method. It is concluded that the damage degree of stress sensitivity of the quartz core fracture is very weak, and the stress change has little effect on the crack width after the treatment of adding and unloading pressure. By using permeability method, environmental scanning electron microscope method and resistivity method, single factor analysis and orthogonal test were carried out on the factors affecting the preparation time, temperature and acid ratio of the chemical corrosion method. The results showed that: with the increase of temperature, With the increase of reaction time and HF concentration, the crack width becomes wider. At the level of orthogonal experimental design, the preparation conditions of the minimum slit width are as follows: temperature 20 鈩，

本文編號(hào)：1793379