Surface Production Operations

2021 ◽  
Keyword(s):  
2021 ◽  
Author(s):  
Chang Siong Ting ◽  
Nur’ain Minggu ◽  
Dahlila Kamat ◽  
Latief Riyanto ◽  
Chee Seong Tan ◽  
...  

Abstract Well B-2 is a dual-string producers with Distributed Temperature Sensing (DTS) fiber installed along the long string (i.e. Well B-2L) across the reservoir sections. Each zone comprises of sub-layers. This system enabled the operator to continuously monitor the wellbore temperature across all the producing intervals including gas-lift monitoring, well integrity identification, zonal inflow profiling and stimulation job evaluation. This paper mainly discusses the post matrix acid stimulation job with interpreted DTS and zonal Permanent Downhole Gauge (PDG) data. Well B-2L has been selected for matrix acidizing treatment to improve the productivity due to potential formation damage, proven by the declining production over the years. Prior to the execution of the acidizing job, several conformance jobs such as injectivity test, tubing pickling were performed. This is followed by the main acid treatment and flow back. DTS & zonal PDG data were acquired throughout the operation. A transient simulator model was built incorporating all the reservoir properties including well trajectory and completion schematic to analyze the DTS profile and understand the zonal inflow profiling for each zone post treatment. A baseline temperature was acquired for the geothermal evaluation. The DTS data has been studied according to actual event schedules. Some significant findings are; i) completion accessories effect (feedthru packers) creates temperature anomalies, ii) leak points detected at top producing zone signifies cooling effect due to injected fluid. The main treatment was intended at zone 2 and 3 using nitrified acid. However, leak points at top zone caused bypassed injection into Zone 1 and 2 instead. Fiber optic DTS warmback profiles post main-treatment was analyzed to quantify the fluid intake from sub-layer in each zone. Qualitatively from the DTS-interpreted zonal profiling, the data clearly shows most of treatment fluid is being injected into Zone 1 and 2 with no intakes at Zone 3. Furthermore, warmback analysis confirmed the high intake zones from sub-layers within the main zone based on the permeability contrast. This paper will further discuss the zonal injectivity understanding for improvement from the zonal-inflow profiling evaluation by incorporating DTS, PDG and surface production data.


Author(s):  
Gregor Steinhagen ◽  
Johannes Braumann ◽  
Jan Brüninghaus ◽  
Matthias Neuhaus ◽  
Sigrid Brell-Cokcan ◽  
...  

Author(s):  
P. A. Tyler ◽  
S. L. Pain

Examination of the reproductive biology of three closely related sympatric astropectinid asteroidshas revealed two distinct reproductive strategies. In Plutonaster bifrons and Dytaster insignis the gonads are serially arranged and open at gonopores located at the tip of genital papillae found on the dorsal arm surface between the bases of the paxillae. The ovaries of these species produce numerous small (ca. 120/«n diameter) eggs which in Plutonaster bifrons appear to show a distinct synchrony of production. Initiation of gametogenesis occurs in June to August of each year with oocyte growthcontinuing until March with a spawn-out in the period March to early June. In specimens where spawningdoesnot occur, there would appear to be internal oocyte degeneration, or after spawning relict oocytesundergo phagocytosis. In males initiation of spermatogenesis may occur in August/September of eachyear but after this synchrony of sperm development is not evident. In Psilaster andromeda gonads are located at the base of the arms and each gonad opens at a single gonopore. A number of small (<300 /«n) oocytes are produced by each gonad. Some of these are phagocytosed and some undergo vitellogenesis and grow to a maximum size of 950 fim before being spawned. Unspent oocytes undergo internal degeneration. In neither females nor males is there any evidence of reproductive synchrony. From these egg sizes, fecundities and gametogenic strategies, we infer indirect planktotrophic development for Plutonaster bifrons, the transfer of a seasonal surface production to deep water providing a food source for developing larvae. The egg size and or close to the sea-bed, as there is no evidence of brooding in this species.


2018 ◽  
Author(s):  
Roman A. DiBiase

Abstract. Interpreting catchment-mean erosion rate from in situ produced cosmogenic 10Be concentration in stream sands requires calculating the catchment-mean 10Be surface production rate and effective mass attenuation length, both of which can vary locally due to topographic shielding and slope effects. The most common method for calculating topographic shielding accounts only for the effect of shielding at the surface, leading to catchment-mean corrections of up to 20 % in steep landscapes, and makes the simplifying assumption that the effective mass attenuation length for a given nuclide production mechanism is spatially uniform. Here I evaluate the validity of this assumption using a simplified catchment geometry to calculate the spatial variation in surface skyline shielding, effective mass attenuation length, and the total effective shielding factor for catchments with mean slopes ranging from 0° to 80°. For flat catchments (i.e., uniform elevation of bounding ridgelines), the increase in effective attenuation length as a function of hillslope angle and skyline shielding leads to a catchment-mean total effective shielding factor of one, implying that no topographic shielding factor is needed when calculating catchment-mean vertical erosion rates. For dipping catchments (as characterized by a plane fit to the bounding ridgelines), the catchment-mean total effective shielding factor is also one, except for cases of extremely steep range-front catchments, where the shielding correction is counterintuitively greater than one. These results indicate that in most cases, topographic shielding corrections are inappropriate for calculating catchment-mean erosion rates, and only needed for steep catchments with non-uniform distribution of quartz and/or erosion rate. By accounting only for shielding of surface production, existing shielding approaches introduce a slope-dependent systematic error that could lead to spurious interpretations of relationships between topography and erosion rate.


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