Penentuan Laju Korosi dan Sisa Umur Pakai Pipa pada Jalur Pipa Transportasi Crude Oil RDL D 07 – SP Rengasdengklok di PT Pertamina EP Asset 3 Tambun Field, Desa Kedung Jaya, Kecamatan Babelan, Kabupaten Bekasi Provinsi Jawa Barat

Abstract

Abstract. PT Pertamina EP Asset 3 Tambun Field, one of the operating units of PT Pertamina EP which is engaged in the upstream oil and gas sector. Production of Tambun Field is dominated by natural gas with an average production of 24,80 MMSCFD(Million Standard Cubic Feet per Day) and oil of 1808 BOPD (Barel Oil Per Day) (Data in April 2018). PT Pertamina EP Asset 3 Tambun Field uses metal pipes in the crude oil transportation process from RDLD07 to SP Rengasdengklok. In use, there can be damage or leakage in the pipe due to corrosion. Corrosion is the process of decreasing the quality of metal materials caused by electrochemical reactions between metal materials and ions found in their environment. Supervision and control of corrosion can detect early and prevent leakage and reduce the remaining life using crude oil transportation pipes. Corrosion monitoring activity aims to determine the type of corrosion, determine the application of protective coating layers on pipeline, corrosion rate of the pipeline, and to determine the remaining service life of the pipeline. Transportation pipeline of crude oil from process from RDLD07 to SP Rengasdengklok has a pipe above the ground (using a buffer) along 635 meters and an underground pipeline along the 2376 meters. In this research obtained soil pH ranged from 5 – 6,8 and soil resistivity between 2300 - 5600 ohm.cm. The effect of soil pH and soil resistivity on the corrosion rate is that the lower the soil pH, under acidic and low resistivity conditions, including high corrosivity. Measurements of the actual thickness of pipeline was done by using ultrasonic thickness gauge (GE Inspection Technologies DM5E) and has a total of 26 measurement points with a total length of 3011 m along the pipeline. Corrosion rate and remaining service life of pipeline transportation can be measured based on actual thickness measurements. The corrosion that occurred in transportation pipeline was uniform corrosion and pitting corrosion. The methods that are used at PT Pertamina Ep Asset 3 Tambun Field for protecting the pipeline from corrosion occurrences are Polyken Pipeline Liquid Adhesive no 1027 and for wrapping used Polyken 980/955.The corrosion rate is between 0,099 – 0,35 mm/year and based on relative corrosion resistance, it belongs to good category. The remaining service life of the transportation pipeline of crude oil is between 1 -  21,41 years and only 3 test points passed the design life, the percentage was only 11.5% of 26 test points.

 Keywords: Transportation Pipeline, Crude Oil, Corrosion Rate, Remaining Service Life, Ultrasonic Thickness Gauge DM 5E 

Abstrak. PT Pertamina EP Asset 3 Tambun Field salah satu unit operasi PT Pertamina EP yang bergerak di sektor hulu migas. Produksi Tambun Field didominasi oleh gas alam dengan rata – rata produksi sebanyak 24,80 MMSCFD(Million Standard Cubic Feet per Day) dan minyak bumi sebesar 1808 BOPD (Barel Oil Per Day) (Data april 2018). PT Pertamina EP Asset 3 Tambun Field menggunakan pipa logam pada transportasi crude oil dari RDL D 07 ke SP Rengasdengklok. Pada penggunaannya dapat terjadi kerusakan atau kebocoran pada pipa akibat korosi. Korosi adalah proses penurunan kualitas material logam yang disebabkan oleh reaksi elektrokimia antara material logam dengan ion – ion yang terdapat di lingkungannya. Pengawasan dan pengendalian terhadap korosi dapat mendeteksi dini dan mencegah terjadinya kebocoran akibat korosi dan pengurangan sisa umur pakai pipa. Penelitian korosi pada pipa transportasi crude oil bertujuan untuk mengetahui jenis korosi yang terjadi, metoda pengendalian korosi yang diaplikasikan, laju korosi dan sisa umur pakai pipa. Jalur pipa transportasi crude oil RDL D 07 - SP Rengasdengklok memiliki pipa di atas tanah (menggunakan penyangga) sepanjang 635 meter dan jalur pipa di bawah permukaan tanah (underground) sepanjang 2376 meter. Pada penelitian ini, pH tanah berkisar antara 5 – 6,8 dan resistivitas tanah 2300 - 5600 ohm.cm. Pengaruh pH tanah dan resistivitas tanah terahadap laju korosi yaitu semakin rendah pH tanah maka dalam kondisi asam dan resistivitas rendah maka termasuk korosif yang tinggi. Pengukuran tebal aktual pipa dilakukan dengan menggunakan alat Ultrasonic Thickness Gauge (GE Inspection Technologies DM5E) pada 26 test point dengan panjang total jalur pipa adalah 3011 m. Berdasarkan data pengurangan ketebalan pipa maka dapat dihitung laju korosi dan sisa umur pakai pipa. Jenis korosi yang terjadi pada pipa transportasi crude oil, yaitu korosi merata dan korosi sumuran. Metoda pengendalian korosi yang diaplikasikan di PT Pertamina EP Asset 3 Tambun Field adalah dengan menggunakan metoda coating dengan jenis Polyken Pipeline Liquid Adhesive no 1027 dan wrapping menggunakan Polyken 980/955. Laju korosi pipa adalah 0,099 – 0,350 mm/tahun dan berdasarkan ketahanan korosi relatif tergolong ke dalam kategori good. Sedangkan sisa umur pakai pipa transportasi crude oil adalah 1 -  21,41 tahun dan hanya 3 test point yang melewati umur desain, persentase 11,5% dari 26 test point.

Kata kunci : Pipa Transportasi, Crude oil, Laju Korosi, Sisa Umur Pakai, Ultrasonic Thickness Gauge DM 5E.