Achieving undersea pipeline integrity through the use of an internal inspection tool

[[abstract]]石油是二十世紀人類最為倚賴的能源，時至今日仍無其他能源可以完全取代它，過於倚賴石油、大量開採下石油存量已日趨枯竭，人類除了尋求替代能源外，根本之道還是在於珍惜石油能源，不浪費石油能源基本作法可從避免洩漏耗損著手做起。原油在儲運的過程中、經常看到因設備問題而造成洩漏污染的新聞，例如2003年3月英國BP石油公司在阿拉斯加的原油管線因為銹蝕洩漏，造成20萬加侖原油外洩、就是一個例子。 石化管線設備本體的腐蝕損壞、常是造成油料管線洩漏的重要關鍵因素，海管亦是如此，為了防止管線因腐蝕而洩漏，必須了解掌握管線現況及本體結構強度，藉由對管線的檢測可以確實掌握管線狀態，但海管位於海底下，檢測上面的困難及經費考量、皆非陸地上管線檢測所能比擬，因此海管在傳統檢測上，只有利用管內壓力測試來檢測海管當下是否堪用，或以量測陰極防蝕電流電位是否達到標準、管線在海面下的狀況無法掌握了解。 鑑於海管檢測上的困難、以及對海管狀況的掌握明瞭，本論文將研究分析適合原油海管的檢測技術、檢測方法、設備與工具，並藉由檢測研究分析海管結構強度，海管腐蝕狀況、腐蝕缺陷大小、形狀及腐蝕形態，計算海管腐蝕率及剩餘壽命、海管可靠度。 研究結果，海管設備剩餘壽命保守估計約22年。唯外力及天然災害非自我所掌握，維修管理及緊急應變處理計劃必須擬定實施，將海管風險危害降至最低。[[abstract]]Fossil oil has been the energy source on which human beings most rely since the 20th Century Till now no other form of energy can totally replace it But human beings' over-reliance on Fossil oil and excessive exploitation have been depleting oil reserves In addition to looking for alternative energy sources the radical solution is to save oil energy A fundamental method for saving oil energy is to prevent oil loss associated with oil leaks Oil leak incidents from subsea pipelines are not rare and are usually accompanied by oil pollution to surrounding environment Take the Mar 2003 incident in Alaska as an example 200 000 gallons of crude oil escaped from BP’s heavily corroded pipeline Corrosion of pipe material is a major cause behind oil/fuel pipeline leaks which can only be prevented through monitoring and assessment of pipeline integrity However the internal of the pipeline is not easily accessible with traditional approaches This can be achieved by means of special types of pipeline inspection tools which are not only difficult but also extremely expensive Although numerous protective measures such as cathodic protection has been applied to the pipeline as it was fabricated and installed the condition of pipeline is still unknown The Pipeline Inspection Tool (PIT) was selected as the vehicle for transporting sensors in and out of the pipeline due to its balanced performance in cost effectiveness and potential risk level With the inspection data collected locations and dimensions of the most heavily corroded spots are then identified and marked by the GPS utility We then proceed to compute the effects of corrosion rate of deterioration due to corrosion and remaining life of the pipeline Results of the study indicate that the pipeline is mostly in good shape with roughly 22 years of remaining life available However it is suggested of the study to strengthen the maintenance plan and emergency response measures in order to be better prepared for the potential hazards of external forces and natural disaster