Pilot test of CO2 flooding at Sarukawa oil field

Summary Achieving effective results using conventional thermal recovery technology is challenging in the deep undisturbed reservoir with extra-heavy oil in the LKQ oil field. Therefore, in this study, a novel approach based on in-situ combustion huff-and-puff technology is proposed. Through physical and numerical simulations of the reservoir, the oil recovery mechanism and key injection and production parameters of early-stage ultraheavy oil were investigated, and a series of key engineering supporting technologies were developed that were confirmed to be feasible via a pilot test. The results revealed that the ultraheavy oil in the LKQ oil field could achieve oxidation combustion under a high ignition temperature of greater than 450°C, where in-situ cracking and upgrading could occur, leading to greatly decreased viscosity of ultraheavy oil and significantly improved mobility. Moreover, it could achieve higher extra-heavy-oil production combined with the energy supplement of flue gas injection. The reasonable cycles of in-situ combustion huff and puff were five cycles, with the first cycle of gas injection of 300 000 m3 and the gas injection volume per cycle increasing in turn. It was predicted that the incremental oil production of a single well would be 500 t in one cycle. In addition, the supporting technologies were developed, such as a coiled-tubing electric ignition system, an integrated temperature and pressure monitoring system in coiled tubing, anticorrosion cementing and completion technology with high-temperature and high-pressure thermal recovery, and anticorrosion injection-production integrated lifting technology. The proposed method was applied to a pilot test in the YS3 well in the LKQ oil field. The high-pressure ignition was achieved in the 2200-m-deep well using the coiled-tubing electric igniter. The maximum temperature tolerance of the integrated monitoring system in coiled tubing reached up to 1200°C, which provided the functions of distributed temperature and multipoint pressure measurement in the entire wellbore. The combination of 13Cr-P110 casing and titanium alloy tubing effectively reduced the high-temperature and high-pressure oxygen corrosion of the wellbore. The successful field test of the comprehensive supporting engineering technologies presents a new approach for effective production in deep extra-heavy-oil reservoirs.

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Carbon Dioxide Displacement of a West Texas Reservoir Oil

Society of Petroleum Engineers Journal ◽

10.2118/9785-pa ◽

1982 ◽

Vol 22 (06) ◽

pp. 805-815 ◽

Cited By ~ 7

Author(s):

William F. Yellig

Keyword(s):

Mass Transfer ◽

Phase Equilibria ◽

Oil Recovery ◽

Miscible Displacement ◽

Pilot Test ◽

Co2 Flooding ◽

Process Data ◽

Analytical Technique ◽

West Texas ◽

Pilot Tests

Yellig, William F., SPE, Amoco Production Co. Abstract This paper presents results of an extensive study to understand CO2 displacement of Levelland (TX) reservoir oil. The work was conducted to support Levelland CO2 pilots currently in progress. Experimental displacement tests were conducted at various pressures, core lengths, and CO2 frontal advance rates. The experimental system included a novel analytical technique to obtain effluent compositional profiles within the oil-moving zone at test conditions. The results of this study show that at pressures greater than the CO2 minimum miscibility pressure (MMP), a multicontact miscible displacement mechanism predominates. Miscibility is developed in situ by vaporization or extraction-type mass transfer. The laboratory lengths required for CO2 to develop miscibility and exhibit miscible displacement efficiency were found dependent on the phase equilibria of the CO2/Levelland oil system. Displacements requiring the greatest length to develop miscibility were at pressures where single-contact mixtures of CO2 and Levelland oil form two liquid phases. A companion paper demonstrates the use of the analytical technique developed in this study to obtain process data from a CO2 field pilot test. In addition, the mechanistic information obtained from this study is used to interpret the process data from the pilot test. The results have application to other reservoir oils whose phase equilibria with CO2 are similar to the CO2/ Levelland oil system. Introduction Miscible CO2 flooding is developing rapidly as a commercial enhanced oil-recovery process. The successful design and interpretation of CO2 pilot tests and fieldwide floods are dependent on a good knowledge of the reservoir and the CO2 displacement process. The overall CO2 displacement process is shown schematically in Fig. 1. The main focus of this study concerned the oil moving zone (OMZ) and particularly the mechanisms by which this zone formed and by which CO2 displaced Levelland oil. Levelland oil was chosen because it is typical of many west Texas reservoir oils being considered for CO2 flooding. In addition, the CO2 pilot tests currently conducted in the Levelland field provide a direct application of this research. Several authors have discussed the displacement of reservoir oil by CO2. These discussions have centered around three primary displacement mechanisms: immiscible, multicontact or developed miscible, and contact miscible. In addition, two basic types of mass transfer have been postulated as responsible for the development of miscibility in a multicontact process: transfer of hydrocarbons from the in-place oil to the displacing CO2 (i.e., vaporization or extraction) and transfer of CO2 to the in-place oil (i.e., condensation). Vaporization and extraction are the same basic mass-transfer process. Vaporization refers to mass transfer from a liquid oil phase to a CO2-rich vapor phase and extraction refers to mass transfer from a liquid oil phase to a CO2-rich liquid phase. The distinction between vaporization and extraction is somewhat arbitrary in describing the CO2 process since it reflects the types of phases present only on first contact. One purpose of this paper is to present results of a comprehensive study to determine the mechanism by which CO2 displaces Levelland oil at reservoir conditions. SPEJ P. 805^

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Study on Pulse Characteristic of Produced Crude Composition in CO2 Flooding Pilot Test

Geofluids ◽

10.1155/2018/2968629 ◽

2018 ◽

Vol 2018 ◽

pp. 1-5

Author(s):

Pengxiang Diwu ◽

Tongjing Liu ◽

Zhenjiang You ◽

Ganggang Hou ◽

Runwei Qiao ◽

...

Keyword(s):

Carbon Number ◽

Pilot Test ◽

Co2 Flooding ◽

Pulse Characteristic ◽

Heterogeneous Model ◽

Injection Volume ◽

The Core ◽

Reservoir Models ◽

Nonmonotonic Function ◽

Nonmonotonic Variation

It has been observed in many laboratory tests that the carbon number of the maximum concentration components (CNMCC) of produced oil varies monotonically with CO2 injection volume at the core scale. However, in CO2 flooding pilot test at the field scale, we find that the CNMCC is usually nonmonotonic function of CO2 injection volume, which is called “pulse characteristic” of CNMCC. To investigate the mechanism of this phenomenon, we analyze the physical process of CO2 flooding in heterogeneous reservoir and explain the reason of the pulse characteristic of CNMCC. Moreover, two 3D reservoir models with 35 nonaqueous components are proposed for numerical simulation to validate the conjecture. The simulation results show that pulse characteristic of CNMCC only occurs in the heterogeneous model, confirming that the pulse characteristic results from the channeling path between wells, which yields nonmonotonic variation of oil-CO2 mixing degree. Based on it, a new method can be developed to identify and quantify the reservoir heterogeneity.

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