Quantification of Fluid Production Distribution in Deviated Wells with High Gas-Liquid Ratio Using a Flow Array Sensing Tool

The objective of this paper is to depict the quantification of the production rates of the different phases in deviated wells with high gas-liquid relation using the Flow Array Sensing Tool (FAST). The readings of standard Production Logging Tools (fullbore flowmeter, density, and capacitance) are centralized, therefore they are affected if there is re-circulation of the heavy phase (liquid). The phase segregation and possible apparent down flow of the heavy phase makes it very difficult to determine the distribution of the produced fluids, and in some cases the spinner flowmeter tends to stop or gives inaccurate readings. The cause of these inaccurate readings is that the centralized spinner is affected by positive flow in the high side and negative flow in the low side of the wellbore, and the spinner shows no flow or even apparent downhole flow, when there is a real positive flow. The FAST tool used during the acquisition of the production logs is an ultracompact production logging tool (3 ft long) that is capable to measure multiphase flows with an array of 8 sensors, two in each arm and located 90° apart. These sensors are based on MEMS (Microelectromechanichal Systems), and among the interchangeable sensors we have optical probes that takes ultra-rapid measurements of the refractive index and can determine hold-up of water, oil and gas; the electrical probes that measures conductivity to differentiate hydrocarbons from water, and magnetic probes with micro-spinners to determine the flow rate. Both the three phase optical probes and the electrical probes have excellent response including water hold-ups over 90% that cannot be measured with a standard capacitance tool. The data logged with FAST in deviated wells was processed and interpreted to obtain the apparent flow velocity profiles of each of the 4 micro-spinners and with the three phase optical probes, and the relative bearing curves the velocity maps, and hold-up maps where obtained. The velocity map showed that there was negative flow in the low side of the well and positive flow in the high side while the hold-up map showed the light phase (gas) in the high side of the well. Both maps showed clearly the flow pattern and were used to quantify the production of each perforation and the total rate matched closely the surface rate (within 2% deviation). With the hold-up and velocity maps, the real flow rates were obtained with high confidence, and the flow pattern were shown clearly in deviated wells. The three phase optical probes, and electrical probes are excellent indicators of water and hydrocarbons inflow in a wide range of hold-ups.

ANALISIS KEGAGALAN SCREW PENYEBAB KERUSAKAN DECANTER SHAFT PADA UNIT PENGOLAHAN MINYAK

Decanter merupakan mesin industri pada unit pengolahan minyak yang berfungsi untuk memisahkan sludge dari crude oil tank menjadi light phase, heavy phase dan solid  dalam crude oil sehingga proses pemisahan selanjutnya di dalam clarier settling tank akan lebih sempurna. Shaft merupakan salah satu bagian dari decanter yang berhenti beroperasi setelah pengoperasian satu tahun. Selanjutnya setelah dilakukan investigasi di tempat kejadian menunjukkan bahwa screw dari shaft mengalami patah sehingga menyebabkan decanter berhenti beroperasi. Hasil pemeriksaan visual menunjukkan bahwa screw mengalami perpatahan/rusak di daerah radius. Sedangkan pemeriksaan fraktografi menunjukkan bahwa foto makro permukaan patahan screw berupa patah ulet yang berawal dari satu sisi dan merambat hingga mencapai penjalaran retak sebesar 70%, namun patah sisa/patah akhir yang terletak berseberangan dengan patah awal. Hasil pemeriksaan tersebut juga dikonfirmasi dengan pemeriksaan metalografi yang menunjukkan adanya inklusi pengotor di lokasi perpatahan screw. Oleh karena itu, cacat inklusi akibat proses manufaktur berperan sebagai inisiasi perambatan retak, lalu menjalar akibat pembebanan dinamis dari pergerakan shaft sampai akhirnya baut mengalami perpatahan. Analisis kimia dari material screw menunjukkan bahwa material screw yang diperiksa merupakan jenis low alloy steel yang sesuai dengan spesifikasi standard.

Hydrodynamic and Mass-Transfer Characteristics of Annular Centrifugal Contactors on the Caprolactam Recovery from Waste Liquor

Caprolactam recovery from waste water is an important and challenging problem in industry. In comparison with extraction columns widely applied in the recovery of caprolactam, annular centrifugal contactor is featured by compact structure, convenient maintenance, and high throughput and efficiency with low energy consumption, etc., which have a wide application in industry. The effects of flow ratio, radius of heavy phase weir and the rotational speeds on entrainment, separation capacity and mass transfer efficiency were studied with annular centrifugal contactors for caprolactam recovery. The results show that the caprolactam with 99.99% purity, the maximum separation capacity of 109L and the highest mass transfer efficiency of 99.8% were obtained.

DRYING STUDY OF EUCALYTPTUS STAIGERIANA LEAVES BY MONITORING THE HUMIDITY OF THE DRYER DISCHARGE

The drying phenomenon can be treated as simultaneous heat and mass transfer in both the light and heavy phases. In the present case, the phenomenon’s evolution is normally observed through the heating of and moisture removal from the heavy phase. On the other hand, while the material is heating, the light phase is cooling and humidifying. The goal of the present work is to present discharge air humidification curves as a function of the drying time for Eucalyptus staigeriana leaves drying experiments. For the air humidification measurements, a dry bulb thermocouple and relative humidity transducer were installed at both the dryer inlet and outlet. The dryer was linked to a data acquisition system, which recorded the dry bulb temperature and the relative humidity with time. These data were later used to calculate the air moisture content at the dryer inlet and outlet. The data obtained by this methodology are compared with the ones from drying kinetic (moisture content removing of the heavy phase along time), acquired by the evolution of wet material weight through the use of an analytical scale.

DRYING STUDY OF EUCALYTPTUS STAIGERIANA LEAVES BY MONITORING THE HUMIDITY OF THE DRYER DISCHARGE

The drying phenomenon can be treated as simultaneous heat and mass transfer in both the light and heavy phases. In the present case, the phenomenon’s evolution is normally observed through the heating of and moisture removal from the heavy phase. On the other hand, while the material is heating, the light phase is cooling and humidifying. The goal of the present work is to present discharge air humidification curves as a function of the drying time for Eucalyptus staigeriana leaves drying experiments. For the air humidification measurements, a dry bulb thermocouple and relative humidity transducer were installed at both the dryer inlet and outlet. The dryer was linked to a data acquisition system, which recorded the dry bulb temperature and the relative humidity with time. These data were later used to calculate the air moisture content at the dryer inlet and outlet. The data obtained by this methodology are compared with the ones from drying kinetic (moisture content removing of the heavy phase along time), acquired by the evolution of wet material weight through the use of an analytical scale.