On May 8, 2016, with the co開西operation of Shenzhen o討爸ffshore oil engineering U南吧nderwater Technology Co., Ltd. 花放and the maintenance and repair你章 center of China Pet是不roleum Pipeline Bureau, the offshore信短 project team of Shenzhen 動懂Shanye Industry Co., Ltd. fought c費的ontinuously for 30 days and nights, Co窗風mpleted the und線低erwater pressurized opening and煙化 underwater structure installation of機見 large-diameter na城北tural gas subsea pipeline 務業connecting Yacheng Hong Kong subsea妹黃 pipeline kp694 node of Dongf喝黃ang 13-2 gas field 店懂group, which is the leading子購 in China. Shenzhen offs裡男hore oil engineer能輛ing Underwater Tech間木nology Co., Ltd. and CNOOC Zhanjiang B城算ranch successively sent數街 letters of thanks to 火舞commend Shanye company for its outst鐘可anding contribution to Yacheng s不聽ubmarine pipeline m事謝aintenance projec費是t.

Yacheng 13-1 gas f一車ield is located in the sea a影信rea about 90km s你熱outh of Hainan Island麗靜. The 28 inch submarine natural gas 樂上pipeline in this ope人志ration connects the offshore platform行可 of Yacheng gas field and Hong 爸訊Kong CLP longgutan power plant,空相 with a total length of about 778km an影什d the first pipe店厭line transmission pressure in the wor個行ld. It is an important ga分媽s transmission tr近購unk line connecting the we光知st of the South 員火China Sea, the east of the South C銀購hina Sea, the Pe答信arl River Delta and Hong 木要Kong, It is the only channel for C弟民NOOC natural gas transmission to Hong K友視ong and the main謝話 source of gas for Hong Kon場分g citizens. It has b放快een supplying gas to Hong K個妹ong China Light and power company fo小習r 20 years. The o離秒pening at kp694 node of Sha要暗nye company is to reserve the 自場output channel for the subsequent Dongf民通ang and Wenchan就城g gas fields af也嗎ter they are connected to人離 the pipeline.

The project has a large openi也得ng diameter and high air pres她雪sure in the pipe. Because the議金 opening machine needs to pas她從s the pre installed 28 inch bal跳暗l valve, the opening strok草事e reaches 3156mm, and the行海re is no finalized opening 頻妹product in the worl謝見d. Moreover, the installat舊爸ion and positioning accur歌近acy of mechanical tee for opening 爸生and its sealing require extrem裡火ely high surface finish o朋房f submarine pipe. On th唱報e one hand, how t不近o safely and ef計離ficiently open h北日oles in underwater low visibi在話lity and high-pressure e少影nvironment is an internatio雨那nal problem. On the other hand,也秒 the project also und但討ertakes the political task of 對上completing within the specified愛紅 time to ensure normal gas supply and 謝那maintain social stability in遠下 Hong Kong.

Since the end of 2015, Sh場人anye company has active飛舞ly contacted the ow錯件ner for technical pre笑裡paration, participated in the research視水 on installation process detail服你s, land commissioning and training 這是at the first time, put fo都笑rward many suggestions on報計 optimizing underwater installa到鄉tion and structural transformation,跳刀 designed underwater fixtu件媽res targeted, and imp哥會roved the const很少ruction scheme. After the start of the離笑 project, the com著生pany gathered the main divers 秒會with long-term op玩訊eration experience in muddy wat子又er and adopted a ful場短l set of diving equipment in秒子 line with international s票刀pecifications approved by IMCA 你計D023. After 30 days and nights of 區坐continuous struggle, the offshore 個水project team has overcome the problems 女外such as tight construction period, poor司從 seabed visibility, hi這身gh installation accuracy, u河資nstable wind, wave and current, i服近nsufficient performance of鐘讀 supporting ship crane and 24-hour u南線ninterrupted operation. 木醫We are not afraid of h熱了ardships and challenges. We have飛員 successfully completed all the 司腦assigned tasks according to the req化麗uirements of the owner, The constru下舊ction technology of underwater instal我農lation of domestic drilling mac車畫hine and other auxiliary structures 城見on the in-servi是商ce natural gas subm大體arine pipeline un來場der the restrictio黃刀n of poor underwater vi開舞sibility is explored.

Underwater opening of submarine pip去綠eline is an important means for emerg遠在ency maintenance and pipe netw費鄉ork modification. The successful imple我還mentation of kp694 underwater ins輛請tallation process of pres內村surized opening has accumulated能黃 a lot of practical experien人謝ce for the company to carry out 用可similar projects under the condi們河tions of poor underwater visi科下bility in the future. A影鐵t the same time, it has中離 also driven the R & D and applicat河冷ion of tooling equipment such as subma草著rine pipe longitudinal w的山eld grinding and submarine pipe 土區polishing, It has effecti報關vely promoted the improvement討作 of the company's u謝報nderwater engineering stre村跳ngth.

(text / figure: Underwat開慢er Engineering Departmen頻業t of Shanye compa票書ny)