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"Seismic waves used for exploration of geological structures are mostly generated from blast sources. A new blasting vibroseis apparatus, which utilizes the homogeneity, isotropy, and incompressibility of water to reduce damage to adjacent rock from blast waves, was developed. This method overcomes the low repeatability and low control issues of traditional blast methods (downhole charge) while maintaining the advantages of high explosive power, sharp pulse signal, and a wide range of frequency domains. Blasting vibroseis and traditional blasting tests were implemented in the Three Gorges Reservoir Region, China. The finite element method (FEM) method was used to numerically calculate blasting vibroseis-induced dynamic ground pressures. Through a series of comparison tests, the characteristics of the seismic waves generated by blasting vibroseis were summarized and the repeatability and controllability of the blasting vibroseis test was validated. The blasting vibroseis apparatus was then used to detect geological structures below the surface of the Maoping landslide, China, and the results were very consistent with previous drilling exploration (89%), which reflects the practical value of the new blasting vibroseis for the exploration of geological structures. Blasting vibroseis can be used as a practical and cost-effective method to detect geological structures."

"Dalam industri migas, proses perhitungan transaksi (custody transfer) banyak dilakukan menggunakan sistem metering. Pada setiap transaksi harus dipastikan sistem metering memiliki performa yang baik dan mampu melakukan pengukuran dengan benar, yang dibuktikan dengan nilai repeatability yang didapat saat proving harus memenuhi standar yang telah disepakati. Di lapangan, terdapat permasalahan berupa variasi laju aliran dari bagian hulu, yang mengganggu proses proving dan mempengaruhi performa sistem metering. Pada penelitian ini dibahas mengenai pengendalian aliran untuk mengkompensasi permasalahan tersebut dan meningkatkan repeatability sistem metering. Sistem metering akan dimodelkan dan dilakukan perancangan pengendali PID menggunakan metode Tempat Kedudukan Akar. Pengujian kemampuan pengendali mengatasi gangguan dilakukan dengan simulasi dengan model yang telah diperoleh. Hasil simulasi menunjukkan sistem metering dengan pengendali PID mampu menghasilkan nilai repeatability yang baik, yaitu dengan variasi gangguan 5% dan 10% didapat nilai 0.0028 dan 0.0013. Sistem juga memiliki overshoot yang kecil, settling time yang cepat, dan steady-state error yang mendekati nol. ......In the oil and gas industry, the process of calculating transaction (custody transfer) is mostly done using metering system. In each transaction must be ascertained that metering system has a good performance and is able to take measurements correctly, and it should be proven with the repeatability value that must meet agreed standard, when proving was carried out. On the field, there are problems from disturbances that caused by flow rate variation from upstream side of the meter, that must affect the proving process, and so the performance of metering system. This report will discuss control of the flow to compensates the disturbances and improve the performance of metering, by improving its repeatability value. Metering system will be modeled and PID controller design will be done by root locus method. The ability of the controller on compensating the disturbances with the model will be simulated. The simulation results show the metering system with PID controllers are able to produce good repeatability value, with the disturbance variation 5% and 10% obtained values 0.0028 and 0.0013. The system also has a small overshoot, fast settling time, and near zero steady-state error."