Hasil Pencarian  ::  Simpan CSV :: Kembali

"

Analisis tekanan bawah permukaan dilakukan untuk mendeteksi adanya overpressure dan permasalahan pada sumur yang akan dilakukan pengeboran berdasarkan data sumur eksplorasi. Pada operasi pengeboran yang dilakukan pada sumur A, B, C, D ditemukan berbagai masalah pengeboran yaitu kick, sloughing shale, dan pipe sticking yang dapat mengakibatkan tingginya Non Productive Time (NPT). Penelitian ini dilakukan untuk: pertama mengidentifikasi mekanisme overpressure di Tight Sand Gas dan Shale Gas pada Sub-Cekungan Jambi. Kedua melakukan prediksi tekanan pori menggunakan metode Bowers dan metode Drilling Efficiency and Mechanical Specific Energy (DEMSE) dan selanjutnya  berdasarkan hasil analisis kuantitatif inversi seismik post-stack  dapat memodelkan tekanan pori di daerah tersebut. Hasil analisis tekanan pori di sumur dan model tekanan pori 3D mengindikasikan bahwa top overpressure terjadi pada Formasi Gumai, kemudian berangsur-angsur turun mendekati tekanan hidrostatik pada Basement. Mekanisme overpressure diakibatkan oleh undercompaction, fluid expansion (kerogen maturation). 4. Formasi Gumai dan formasi Talang Akar merupakan batuan shale sehingga jenis lumpur yang baik digunakan adalah oil based mud (OBM). Batuan shale memiliki sifat elasticity sehingga rate of penetration (ROP) dan weight on bit (WOB) yang digunakan semakin besar.

 

---

The subsurface pressure analysis is used to detect the overpressure and problems in the well that will be drilled based on exploration well data. Various problems were found while drilling operations carried out on A,B,C,D wells, such as kick and pipe sticking which cause a high Non-Productive Time (NPT). This research is conducted to identify the mechanism of overpressure formation in tight sand gas and shale gas in the Jambi Sub-Basin. Furthermore, to predict pore pressure using the Drilling Efficiency and Mechanical Specific Energy (DEMSE) and Bowers methods. The final result will be a 3D pore pressure cube in the area based on quantitative analysis of post-stack seismic inversion. The results of the pore pressure analysis from the wells and the 3D pore pressure model indicate that top of overpressure occurs in the Gumai Formation, then it is decreasing gradually approaching the hydrostatic pressure on the Basement. The mechanisms of overpressure are caused by under compaction, fluid expansion (kerogen maturation). The Gumai Formation and Talang Akar Formation are shale rocks so the type of mud weight that is well used is oil based mud (OBM). Shale rocks have elasticity so that the rate of penetration (ROP) and weight on bit (WOB) that are used is getting bigger.

 

"

"Salah satu parameter penting yang harus dicermati sebelum dilakukan pemboran sumur migas adalah besarnya tekanan di dalam formasi batuan yang akan dilakukan pemboran. Peristiwa kick, loss atau bahkan blowout pada lubang sumur dapat diantisipasi apabila prediksi tekanan pori dilakukan sebelum pemboran dimulai. Prediksi tekanan pori diperlukan untuk mendesain berat jenis lumpur yang digunakan dan lokasi kedalaman casing yang tepat untuk menghindari adanya overpressure pada lubang bor.Tesis ini akan membandingkan tiga jenis metode yang biasa digunakan dalam perhitungan prediksi tekanan pori, yaitu: Metode Equivalent Depth, Metode Eaton, dan Metode Bowers. Ketiga metode tersebut akan dilakukan pada data yang berasal dari sumur dan data seismik dari area Delta Niger untuk melihat perbandingan diantaranya.Hasil penelitian menunjukkan bahwa Metode Equivalent Depth dan Metode Eaton memiliki kemiripan hasil, karena menggunakan parameter input yang hampir sama namun algoritma yang berbeda. Metode Bowers menunjukkan hasil yang paling berbeda karena perhitungannya murni berdasarkan suatu persamaan empiris. Dari ketiga metode tersebut, untuk penelitian di area Delta Niger, Metode Equivalent Depth dan Metode Eaton dianggap paling baik untuk digunakan.

---

One important parameter that must be observed prior to the drilling of oil and gas wells is the amount of pressure inside the rock formations to be drilled. Events such as kick, loss, or even a blowout in the wellbore can be anticipated if the pore pressure prediction is made before drilling begin. Pore pressure prediction is required to design the density of mud used and the exact depth of right casing to avoid overpressure in the borehole.This study will compare three types of methods used in the calculation of pore pressure prediction, which is: Equivalent Depth Method, Eaton Method, and Bowers Method. The three method will be performed on data derived from the well and seismic data from the Niger Delta area to see the comparison between them.The results showed that the Equivalent Depth Method and Eaton Method have similar results due to the input parameters used are almost the same but with different algorithms. Bowers Method showed the most different results because the calculation is based purely on an empirical equation . Of the three methods, for research in the Niger Delta area, Equivalent Depth Method and Eaton Method are considered the best method to use."