Optimisasi dan Kontrol pada Operasi Drilling Dengan Disturbance Pengaruh Perubahan Kedalaman Menggunakan Konsep Plant Wide Control dan Genetic Algorithm

Pemilihan lokasi pengeboran akan mendapatkan lebih banyak tantangan, seperti kedalaman yang lebih ekstrim, keadaan lingkungan dan kondisi formasi lapisan batuan yang beragam. Dengan tantangan tersebut tentunya akan berpengaruh terhadap performa drilling secara keseluruhan. Performa drilling dapat dilihat dari nilai rate of penetration dan pada penelitian ini akan dilakukan analisis terhadap operasi drilling dengan metode plant wide control. Penambahan kedalaman operasi tiap 250 m akan menghasilkan kenaikan tekanan dasar sumur dengan nilai rata rata 36,84 bar, berdasarkan hasil perhitungan dengan teknik optimisasi dengan algoritma genetik, didapatkan nilai laju penetrasi paling optimal ditiap kedalaman operasi drilling. Dengan pengaruh faktor weight on bit didapatkan nilai rate of penetration di tiap kedalaman. Hasil optimisasi pada kedalaman operasi 3000 m dengan ROP 10,4 m/jam, kedalaman 3250 m dengan ROP 7,14 m/jam, kedalaman 3500 m dengan ROP 4,75 m/jam, kedalaman 3750 m dengan ROP 3,05 m/jam dan kedalaman 4000 m dengan ROP 1,90 m/jam. Seiring dengan penambahan kedalaman akan diiringi pengurangan ROP, oleh sebab itu dilakukan pengendalian menggunaan kontrol PID terhadap variabel yang dipengaruhi oleh disturbance perubahan nilai kedalaman. Dengan adanya disturbance tersebut, dirancang pengendalian plant wide untuk mengendalikan perubahan pressure bottom hole. Ketika kenaikan pressure bottom hole, laju injeksi main pump akan diturunkan, lalu bukaan choke valve diperbesar, memungkinkan penurunan pressure choke, lalu injeksi backpump akan diturunkan karena aliran keluar melalui saluran choke meningkat. ================================================================================================================== The choice of drilling location will get more challenges, such as more extreme depths, environmental conditions, and diverse conditions of rock formation. These challenges will certainly affect the overall drilling performance. Drilling performance can be seen from the rate of penetration value and in this study, an analysis of drilling operations using the plant-wide control method is conducted. The addition of operating depth per 250 m will increase bottom well pressure with an average value of 36.84 bar, based on the results of calculations with optimization techniques with genetic algorithms, the optimal penetration rate is obtained at each depth of the drilling operation. With the influence of the weight on bit factor, the rate of penetration value is obtained at each depth. Optimization results at an operating depth of 3000 m with ROP 10,4 m / hour, depth of 3250 m with ROP 7,14 m / hour, depth of 3500 m with ROP 4,75 m / hour, depth of 3750 m with ROP 3,05 m / hour and depth of 4000 m / hour with ROP 1.90 m / hour. Along with the addition of depth will be accompanied by a reduction in ROP, therefore control is used using the PID control of variables that are affected by disturbance changes in the value of depth. With this disturbance, plant wide control is designed to control changes in pressure bottom hole. When the bottom hole pressure rises, the main pump injection rate will be reduced, then the choke valve opening is enlarged, allowing a decrease in the pressure choke, then the back pump injection will be reduced because of the outflow through the choke channel increases