Core Experiment and Stimulation Mechanism of Unstable Waterflooding in Low Permeability Reservoirs

doi:10.7657/XJPG20220417

Abstract

Abstract:

According to the typical characteristics of low permeability reservoirs in Changqing oilfield, parallel core and double-layered core experiments were carried out to simulate the effect of unstable waterflooding in heterogeneous low permeability reservoirs. Due to the poor visibility of core experiments, numerical models for simulating interlayer and intralayer heterogeneous reservoirs were established, which may reveal the stimulation mechanism of unstable waterflooding according to the change of flow field. The results show that for interlayer heterogeneous reservoirs, compared with continuous waterflooding, unstable waterflooding can promote the advancement of the flooding front in the layers with lower permeability, and give full play to capillary force in oil displacement, so unstable waterflooding can significantly improve the oil recovery of the layers with lower permeability, and the pattern of short-term injection combined with long-term quit can enhance the recovery rate the most. For intralayer heterogeneous reservoirs, unstable waterflooding can generate pressure oscillations in the layers to enable the fluid percolation between the higher permeability layers and the lower permeability layers, so that the sweep efficiency of injected water in the lower permeability layers is increased and the recovery rate of the lower permeability layers is enhanced, thereby increasing the total oil recovery rate of the reservoir.

Key words: Changqing oilfield, low permeability reservoir, heterogeneous formation, unstable waterflooding, stimulation mechanism, core experiment, numerical simulation

CLC Number:

TE348

ZHOU Jinchong, ZHANG Bin, LEI Zhengdong, SHAO Xiaoyan, GUAN Yun, CAO Renyi. Core Experiment and Stimulation Mechanism of Unstable Waterflooding in Low Permeability Reservoirs[J]. Xinjiang Petroleum Geology, 2022, 43(4): 491-495.

Figures/Tables 7

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References 20

[1]	马庆涛, 吴洁, 马骁. 大芦湖油田高21块不稳定注水方式研究[J]. 特种油气藏, 2019, 26(6):103-107.
	MA Qingtao, WU Jie, MA Xiao. Transient water injection pattern of Block Gao-21 in Daluhu oilfield[J]. Special Oil & Gas Reservoir, 2019, 26(6):103-107.
[2]	杨丽娜, 王欣然, 史长林, 等. 潜山裂缝油藏不稳定注水体系研究[J]. 重庆科技学院学报(自然科学版), 2020, 22(2):10-14.
	YANG Lina, WANG Xinran, SHI Changlin, et al. Research on unsteady water flooding system in buried hill fractured reservoir[J]. Journal of Chongqing University of Science & Technology (Natural Science Edition), 2020, 22(2):10-14.
[3]	潘有军, 谢军, 孟朋飞, 等. 三塘湖油田牛圈湖区块西山窑组油藏注水开发对策[J]. 新疆石油地质, 2020, 41(6):721-728.
	PAN Youjun, XIE Jun, MENG Pengfei, et al. Water injection development strategies for the reservoirs of Xishanyao formation in Niujuanhu block of Santanghu oilfield[J]. Xinjiang Petroleum Geology, 2020, 41(6):721-728.
[4]	吴少诚. 高含水油田层内非均质储层不稳定注水规律实验研究[D]. 北京: 中国地质大学(北京), 2019.
	WU Shaocheng. Experimental study on unstable water injection in heterogeneous interior reservoirs of high water-cut oilfield[D]. Beijing: China University of Geosciences (Beijing), 2019.
[5]	OWENS W W, ARCHER D L. Waterflood pressure pulsing for fractured reservoirs[J]. Journal of Petroleum Technology, 1965, 18(6):745-752. doi: 10.2118/1123-PA
[6]	GUIDROZ M G. E.T. O’Daniel project a successful spraberry flood[J]. Journal of Petroleum Technology, 1967, 19(9):1137-1140. doi: 10.2118/1791-PA
[7]	ARAUJO M. Cyclic waterflooding in homogeneous and layered beadpacks[R]. Vienna,Austria:68th EAGE Conference & Exhibition, 2006.
[8]	田仲强, 王奎升, 张进平. 不稳定注水模拟实验及其在不同类型砂岩油藏中的应用[J]. 石油大学学报(自然科学版), 2000, 24(5):28-31.
	TIAN Zhongqiang, WANG Kuisheng, ZHANG Jinping. Experimental study on the unsteady water injection techniques and oilfield application in different kinds of sandstone reservoirs[J]. Journal of University of Petroleum (Natural Science Edition), 2000, 24(5):28-31.
[9]	王健, 杨胜来, 蒋利平. 轮南油田周期注水物理模拟实验研究[J]. 石油地质与工程, 2011, 25(5):118-120.
	WANG Jian, YANG Shenglai, JIANG Liping. Physical simulation experimental study of cyclic waterflooding in Lunnan oilfield[J]. Petroleum Geology & Engineering, 2011, 25(5):118-120.
[10]	张学刚, 王秀宇, 代春明, 等. 周期注水实验研究及力学机理探讨[J]. 石油化工高等学校学报, 2015, 28(6) :66-70.
	ZHANG Xuegang, WANG Xiuyu, DAI Chunming, et al. Experimental study and mechanism investigation of cyclic waterflooding[J]. Journal of Petrochemical Universities, 2015, 28(6):66-70.
[11]	MENG Qingbang, LIU Huiqing, WANG Jing, et al. Experimental and numerical study on cyclic water injection in stress-sensitive reservoirs:a case study[J]. SPE 180808-MS, 2016.
[12]	张晓, 李小波, 荣元帅, 等. 缝洞型碳酸盐岩油藏周期注水驱油机理[J]. 复杂油气藏, 2017, 10(2):38-42.
	ZHANG Xiao, LI Xiaobo, RONG Yuanshuai, et al. Mechanism of cyclic water flooding in fractured-vuggy type carbonate reservoir[J]. Complex Hydrocarbon Reservoirs, 2017, 10(2):38-42.
[13]	于长海. 西峰油田特低渗透油藏周期采油机理及应用研究[D]. 西安: 西安石油大学, 2018.
	YU Changhai. A mechanism and applied research on intermittent producing to extra low-permeability reservoir in Xifeng oilfield[D]. Xi’an: Xi’an Shiyou University, 2018.
[14]	张本艳, 周立娟, 何学文, 等. 鄂尔多斯盆地红河油田长8油藏周期注水技术研究[J]. 石油地质与工程, 2018, 32(4):79-82.
	ZHANG Benyan, ZHOU Lijuan, HE Xuewen, et al. Research on cyclic waterflooding technology of Chang 8 reservoir in Honghe oilfield,Ordos basin[J]. Petroleum Geology & Engineering, 2018, 32(4):79-82.
[15]	高涛, 赵习森, 党海龙, 等. 延长油田致密油藏注水吞吐机理及应用[J]. 特种油气藏, 2018, 25(4):134-137.
	GAO Tao, ZHAO Xisen, DANG Hailong, et al. Mechanism of cyclic water injection and its application in tight oil reservoirs in Yanchang oilfield[J]. Special Oil & Gas Reservoirs, 2018, 25(4):134-137.
[16]	赵军, 翁大丽, 陈平, 等. 高含水期非均质油藏周期注水室内实验研究[J]. 应用科技, 2019, 46(6):92-95.
	ZHAO Jun, WENG Dali, CHEN Ping, et al. Experimental study on the cyclic water flooding of heterogeneous reservoir in a high water cut stage[J]. Applied Science & Technology, 2019, 46(6):92-95.
[17]	苏彦春, 朱志强. 裂缝性潜山油藏渗流特征及不稳定注水策略:以渤海锦州25-1南油田潜山油藏为例[J]. 中国海上油气, 2019, 31(6):78-85.
	SU Yanchun, ZHU Zhiqiang. Percolation characteristics and unstable water injection strategy of fractured buried hill reservoirs:taking the buried hill reservoir in Bohai JZ25-1S oilfield as an example[J]. China Offshore Oil & Gas, 2019, 31(6):78-85.
[18]	吴少诚. 高含水油田层内非均质储层不稳定注水规律实验研究[D]. 北京: 中国地质大学(北京), 2019.
	WU Shaocheng. Experimental study on unstable water injection in heterogeneous interior reservoirs of high water-cut oilfield[D]. Beijing: China University of Geosciences (Beijing), 2019.
[19]	张利健, 田盼盼, 任宜伟, 等. 海上油田水驱开发注水压力优化[J]. 新疆石油地质, 2021, 42(1):63-67.
	ZHANG Lijian, TIAN Panpan, REN Yiwei, et al. Optimization of water injection pressure in developing offshore oil reservoir[J]. Xinjiang Petroleum Geology, 2021, 42(1):63-67.
[20]	郭红强, 马赞, 白惠文, 等. 低渗油藏水驱油影响因素及机理数值模拟分析[J]. 承德石油高等专科学校学报, 2020, 22(6):15-20.
	GUO Hongqiang, MA Zan, BAI Huiwen, et al. Numerical simulation analysis of influencing factors and mechanism of water flooding in low permeability reservoir[J]. Journal of Chengde Petroleum College, 2020, 22(6):15-20.