CAJ | 학술논문

针对致密性气藏氮气钻完井一体化管柱中超级13Cr 油钻杆和4145H 钻铤螺纹连接的电偶腐蚀问题，模拟工程实际管柱结构，设计出超级13Cr 不锈钢和4145H 碳钢的螺纹连接电偶腐蚀试样，利用高温高压釜模拟井下腐蚀工况，在 CO2分压为1．75 MPa，总压为35 MPa，温度分别为90℃和110℃条件下进行了高温高压腐蚀测试。通过腐蚀失重、扫描电镜（SEM）和EDS 分析测试，得出了模拟井底工况下13Cr 油钻杆材质和4145H 钻铤材质螺纹连接后的电偶腐蚀情况。实验结果表明：模拟工况下，超级13Cr 和4145H 偶合腐蚀后，超级13Cr 无明显腐蚀特征；在13Cr 与4145H 连接处，因电位差和缝隙加速了4145H材质的腐蚀；110℃条件下，4145H 在气相中的腐蚀速率为0．1811 mm／a，由于钻铤壁厚大、腐蚀余量宽，选用4145H 碳钢钻铤能满足生产需求，具有较好的经济适用性。研究成果在塔里木致密气藏氮气钻完井管柱设计中得到应用。
침대치밀성기장담기찬완정일체화관주중초급13Cr 유찬간화4145H 찬정라문련접적전우부식문제，모의공정실제관주결구，설계출초급13Cr 불수강화4145H 탄강적라문련접전우부식시양，이용고온고압부모의정하부식공황，재 CO2분압위1．75 MPa，총압위35 MPa，온도분별위90℃화110℃조건하진행료고온고압부식측시。통과부식실중、소묘전경（SEM）화EDS 분석측시，득출료모의정저공황하13Cr 유찬간재질화4145H 찬정재질라문련접후적전우부식정황。실험결과표명：모의공황하，초급13Cr 화4145H 우합부식후，초급13Cr 무명현부식특정；재13Cr 여4145H 련접처，인전위차화봉극가속료4145H재질적부식；110℃조건하，4145H 재기상중적부식속솔위0．1811 mm／a，유우찬정벽후대、부식여량관，선용4145H 탄강찬정능만족생산수구，구유교호적경제괄용성。연구성과재탑리목치밀기장담기찬완정관주설계중득도응용。
With the galvanic corrosion problem in threaded connection of super 13Cr oil drill pipe and 4145H drill collar of nitrogen drilling and completion integration string in tight gas reservoir,threaded connection galvanic corrosion specimens of super 13Cr stainless steel and 4145H carbon steel were designed by simulating the practical engineering string structure.The high tempera-ture and high pressure (HTHP)corrosion test was conducted in the HTHP autoclave,where the simulated environment includes CO2 partial pressure of 1.75 MPa,total pressure of 35 MPa,and temperature of 90 ℃ and 110 ℃.Through corrosion weight loss,SEM and EDS analysis,galvanic corrosion characteristics were studied.The results show that,under the simulated envi-ronment,there is no obvious corrosion characteristics in super 13Cr steel after coupling corrosion.While in the junction,the cor-rosion of 4145H steel is accelerated due to the potential difference and gap.At 110 ℃,the corrosion rate of 4145H steel in the gas phase was 0.181 1 mm/a.Because of the large drill collar wall thickness and wide corrosion allowance,4145H carbon steel drill collar which has a good economic applicability can meet production demands.The research results have been applied in the design of nitrogen drilling and completion string in Tarim tight gas reservoir.