Difficulties and Countermeasures of Shale Oil Development in Lucaogou Formation of Jimsar Sag

Abstract

Abstract: To realize the effective producing and development of the shale oil resources in the Lucaogou Formation of Jimsar sag and topush the scaled productivity construction of China’s terrestrial shale oil, the paper detailedly compares the geological characteristics of the shale oil reservoirs in China and abroad, analyzes the geological differences between China’s terrestrial shale oil and the marine shale oilin north America, and establishes a series of technical countermeasures for high efficient development of the shale oil in the Lucaogou formation of Jimsar sag based on the researches and practices of the exploration and development in the formation. The study results show thatthe shale oil in the Lucaogou formation of Jimsar sag is characterized by deep burial, poor physical properties and serious heterogeneityetc., and the difficulties encountered during the development mainly include incomplete criterion of sweet spot identification, low degree ofoverall effective producing, uncertain technical parameters for development and lots of difficulties in cost decreasing and benefit increasing, the following work has been carried out to overcome the difficulties encountered during development: 1)Based on the studies of reservoir, logging, mud log, seismic and fundamental mechanics experiment, a set of criterion of “sweet spot” evaluation has been established to optimize favorable geological and engineering area; 2)The study on geology-engineering integration has been performed to optimize well pattern deployment parameters and reasonable working system based on field well-spacing test and production performance analysis. 3) The main factor influencing crude oil fluidity is determined as the viscosity based on the analysis of crude oil fluidity experiment, and then Pad-CO2 fracturing technology can be used to effectively reduce viscosity and increase efficiency. 4) The large-scaled platform batch drillingand fracturing processes have been applied to reduce the impacts of fracturing interference and casing failure on scaled productivity construction, and then to determine the technological direction for decreasing cost and increasing efficiency. The countermeasures formed during the shale oil development in Jimsar sag have a good demonstration effect on large-scaled production of the shale oil resources in China.

Key words: Jimsar sag, Lucaogou Formation, shale oil, development difficulty, countermeasure

HUO Jin, HE Jixiang, GAO Yang, DONG Yan, XU Dongsheng, LI Yingyan. Difficulties and Countermeasures of Shale Oil Development in Lucaogou Formation of Jimsar Sag[J]. Xinjiang Petroleum Geology, 2019, 40(zk(English) ): 379-388.

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