Evaluating Lacustrine Shale Oil Reservoirs by Integrating Reservoir Quality and Organic Matter Quality with Advanced Logging and Core Measurements

Hou, Yu Ting; Xi, Sheng Li; Wu, Yong; Li, Huayang; Zhao, Xianran; Wu, Jiansheng; Zhao, Hongwen

doi:10.2523/iptc-18996-ms

Cited by 3 publications

(1 citation statement)

References 6 publications

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“…Advances in hydraulic fracturing and horizontal drilling technologies have sparked a surge of interest in exploring and exploiting shale oil (Honarpour et al 2012;Hou et al 2016;Zheng and Sharma 2020). Permeability, the most critical property for evaluating the capability of oil flow in shale strata, is essential for the development of shale oil reservoirs (Feng et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Stochastic-based liquid apparent permeability model of shale oil reservoir considering geological control

Wang

Ma³

et al. 2021

J Petrol Explor Prod Technol

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Shale is a complex porous medium composed of organic matter (OM) and inorganic minerals (iOM). Because of its widespread nanopores, using Darcy’s law is challenging. In this work, a two-fluid system model is established to calculate the oil flow rate in a single nanopore. Then, a spatial distribution model of shale components is constructed with a modified quartet structure generation set algorithm. The stochastic apparent permeability (AP) model of shale oil is finally established by combining the two models. The proposed model can consider the effects of various geological controls: the content and grain size distribution of shale components, pore size distribution, pore types and nanoconfined effects (slip length and spatially varying viscosity). The results show that slip length in OM nanopores is far greater than that in iOM. However, when the total organic content is less than 0.3 ~ 0.4, the effect of the OM slip on AP increases first and then decreases with the decrease in mean pore size, resulting in that the flow enhancement in shale is much smaller than that in a single nanopore. The porosity distribution and grain size distribution are also key factors affecting AP. If we ignore the difference of porosity between shale components, the error of permeability estimation is more than 200%. Similarly, the relative error can reach 20% if the effect of grain size distribution is ignored. Our model can help understand oil transport in shale strata and provide parameter characterization for numerical simulation.

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Section: Introductionmentioning

confidence: 99%

Stochastic-based liquid apparent permeability model of shale oil reservoir considering geological control

Wang

Ma³

et al. 2021

J Petrol Explor Prod Technol

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A New Integrated Screening of China Lacustrine Liquids Rich Shale Resource

Bai¹,

Wan

2019

Proceedings of the SPE/AAPG/SEG Asia Pacific Unconventional Resources Technology Conference

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Fracturing and Production Observations from the First Two Horizontal Wells for Shale Oil Exploration in Ordos Basin

Hou

et al. 2020

Day 3 Wed, November 11, 2020

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The continental depositional environment poses unique challenges for the exploration of unconventional resources. The tight reservoir nature requires horizontal drilling and multistage completion. However, the geologic discontinuity and the geomechanical heterogeneity complicate lateral completion design, fracturing treatment execution, and production analysis. The experience of developing the first two horizontal wells for shale oil exploration in the Ordos basin resulted in observations that link the geology, reservoir, geomechanics, and production behaviors, which can be used for future appraisal and development in similar environments. In 2014, one exploration well in the south Ordos basin demonstrated that the source rock from the Chang-7-3 formation could produce good light oil, but the tight reservoir needed horizontal drilling and multistage fracturing completion to achieve the production potential. In 2019, two horizontal wells were placed adjacent to each other for appraisal purposes. Due to the unique lacustrine deposition environment of the Chang-7-3 formation, landing the laterals in the target formation proved to be very challenging even with special geosteering tools. For both wells, the net-to-gross ratio is less than expected (51% and 38%), creating significant challenges for the ensuing completion phase. The multistage completion and fracturing were designed with full consideration of the horizontal lateral conditions. Reservoir quality (RQ), completion quality (CQ), and geology quality (GQ) were considered to optimize the completion staging strategy and fracturing plans. Besides the pressure response during fracturing, two additional monitoring and evaluation systems were deployed during the completion phase: microseismic interpretation and chemical tracers. Observations from these three measurements provided valuable information of how the formation responded to the staging strategy, fracturing initiation and diversion, and flowback and production. Post-fracturing production from both wells met expectations in the testing phase. Additionally, the observations during fracturing and flowback of those two wells provide unique value for better understanding the Chang-7-3 formation. Fracture initiation proved to be feasible only in the lateral sections with proper sand facies where good RQ and CQ were found. Microseismic monitoring showed fracture orientation and planar extension in space. Tracer results revealed where the formation hydrocarbons came from and how the two wells interacted. This case study will have significant influence for future drilling and completion in the Chang-7-3 formation and provide a useful case history for continental shale oil scenarios.

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Evaluating Lacustrine Shale Oil Reservoirs by Integrating Reservoir Quality and Organic Matter Quality with Advanced Logging and Core Measurements

Cited by 3 publications

References 6 publications

Stochastic-based liquid apparent permeability model of shale oil reservoir considering geological control

Stochastic-based liquid apparent permeability model of shale oil reservoir considering geological control

A New Integrated Screening of China Lacustrine Liquids Rich Shale Resource

Fracturing and Production Observations from the First Two Horizontal Wells for Shale Oil Exploration in Ordos Basin

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