Journal of Southwest Petroleum University(Science & Technology Edition) ›› 2025, Vol. 47 ›› Issue (5): 112-120.DOI: 10.11885/j.issn.1674-5086.2023.10.16.01

• OIL AND GAS ENGINEERING • Previous Articles     Next Articles

Fluid Representativeness Evaluation and Fluid Distribution Characteristics of Fuman Oilfield

ZHANG Jie1,2, LIU Zhiliang1,2,3, WANG Peng1, ZHAO Longfei1, TU Hanmin4   

  1. 1. Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China;
    2. R & D Center for Ultra Deep Complex Reservoir Exploration and Development, CNPC, Korla, Xinjiang 841000, China;
    3. State Energy Key Laboratory of Carbonate Oil and Gas, Korla, Xinjiang 841000, China;
    4. National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2023-10-16 Published:2025-11-04

Abstract: The reservoir in the Fuman Oilfield is buried at a depth of more than 7 000 m, with high temperature, high pressure, various types of formation fluids, and complex distribution patterns. A significant amount of sampling work was carried out in the early stages of exploring the Fuman Oilfield. It was discovered that in some samples, the dissolved gas oil ratio in the PVT experiment did not match the production gas oil ratio, failing to reflect the properties of the formation fluid accurately. Consequently, an evaluation method for the representativeness of fluid samples from the ultra-deep, high-temperature, and ultrahigh-pressure Fuman reservoirs has been established based on relevant standards and considering whether the dissolved gas to oil ratio aligns with production performance. The representativeness of samples from 58 wells was evaluated, and the factors affecting sample representativeness were analyzed. The research shows that the main reasons for poor sample representativeness include unstable production conditions in the sampling wells prior to sampling, shallow sampling depth for downhole samples, and the imbalance in oil-gas separation during separator sampling. Among all representative samples, the sample collected by separator sampling accounts for 67.74%, and it is recommended that separator sampling be the primary method for Fuman Oilfield in the future. Based on the representative samples obtained, the overall fluids in the Fuman Oilfield showed a trend of lighter fluids from west to east and from north to south.

Key words: Fuman Oilfield, separator sampling, downhole sampling, representativeness evaluation, fluid distribution characteristics

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