Luo R.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation |
Li R.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation |
Dang Y.,China Oilfield Services Ltd. |
Yang J.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation |
Liu W.,Turpan Hami Oilfield Company
Optical Fiber Technology | Year: 2015
OFDM-ROF (orthogonal frequency division multiplexing-radio over fiber) system has high spectral efficiency and high transmission rate. However, due to the non-linear power amplifier, the high peak-to-average power ratio (PAPR) of the transmission signals is one of the major setbacks in the OFDM-ROF transmission systems. In order to reduce PAPR, this paper proposes two improved selected mapping (SLM) methods without explicit side information (SI): Proposed ED-SLM and Proposed SLM. In the Proposed ED-SLM method, signals will be transmitted without side information which is scrambled by special initial phase sequences and at the receiver an Euclidean phase distance detection (EPD) method is used to detect the SI and finishes the demodulation. In the proposed SLM method, the signals are transformed by Hadamard matrix to reduce PAPR. Then the row vectors of Hadamard matrix are used as phase sequences and superimposed on the data signals. The theory and simulation results show that the two improved SLM methods perform better in PAPR and BER reduction than the conventional SLM method in the OFDM-ROF transmission systems. © 2014 Elsevier Inc. All rights reserved.
Mu J.-F.,Turpan Hami Oilfield Company |
You-Xi L.U.,Turpan Hami Oilfield Company |
Wei S.-L.,Turpan Hami Oilfield Company |
Jiang Y.-Q.,Turpan Hami Oilfield Company |
Liu Y.-M.,Turpan Hami Oilfield Company
Oilfield Chemistry | Year: 2010
Lukeqin oil field was an ultra-deep heavy oil reservoir with block. The average daily output was 5.8 t per well, up to 18 t per well But in the development process,the output of some new horiaontal well couldn' t reach the design requirements together with rapid reduced velocity. When water with room temperature was injected in some wells, the water pressure increased rapidly and injection shortage occurred seriously. The main block of thick oil well was organic block and the secondary one was inorganic block based on the analysis of the block theory for the thick oil well Relieving organic block around the shaft at first could make the add system to access deep of the reservoir efficiently. The relieving reservoir plugging recipe of acid/alkali compound was applied in 12 wells on site and the efficiency was of 100%. Cumulative quantity of oil in 2 production wells was about 4800 t and the production oil of one well increased of 5.9 t per day in average. Valid period of 10 water injection wells was more than 300 days and the absorption index of single well increased of 1.91 m3MPa per day in average.
Liu B.,China University of Petroleum - Beijing |
Liu B.,Northeast Petroleum University |
Huang Z.-L.,China University of Petroleum - Beijing |
Wang M.-M.,Turpan Hami Oilfield Company |
And 2 more authors.
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2011
The oil in Shengbei structure belt of rich hydrocarbon Taibei sag in Tuha basin is sourced from Shuixigou Group and Qiketai Formation lacustrine facies rock resources, and the gas is coal-related gas. Above the hydrocarbon bearing interval of Qiketai Formation, the oil is mainly lacustrine facies oil and the gas is mainly coal-related gas. Below the hydrocarbon bearing interval of Qiketai Formation, the oil is mainly coal-related oil and the main accumulation stage is on Late Tertiary. Allocation relationship on reservoir-forming elements of Shengbei structural belt has controlled the distribution of different oil & gas types in this zone. By means of faults, the lacustrine facies oil of Qiketai Formation in Late Tertiary can preferentially accumulate in the well-physical property of Cretaceous reservoir. From Late Tertiary to Quaternary, the coal-related gas, in the progress of upward migration, can enter the sand with blocked up by heavy crude and short of physical property of reservoir in Kalazha Group and finally generates gas condensate reservoir. Because of the good sealing characteristics of the argillyte in the Middle-Upper Kalazha Group, some of gas migrate continually upward the oil reservoir of Lianmuqin Formation in Cretaceous. Above all, it has nowadays formed the distribution character of oil above and gas below in shallow layer of this area.