期刊
FUEL
卷 297, 期 -, 页码 -出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.fuel.2021.120744
关键词
Fracking; Pore Architecture; Shale Reactivity; Organic Matter; NMR; Gas Adsorption
资金
- Center for Mechanistic Control of Water-Hydrocarbon-Rock Interactions in Unconventional and Tight Oil Formations (CMC-UF), an Energy Frontier Research Center - U.S. Department of Energy, Office of Science under DOE (BES) Award [DE-SC0019165]
- EFRC-MUSE, an Energy Frontier Research Center - U.S. Department of Energy, Office of Science, Basic Energy Sciences [DE-SC0019285]
The hydraulic fracturing stimulation process can change the petrophysical and flow properties of shale matrix in unconventional reservoirs, with interactions with native and exogenous fluids that can impact reservoir productivity. Experimental studies show that the presence of formation fluid restricts pore space access to stimulation fluid, while mineral dissolution and precipitation dominate alterations in pore structure. Organic matter limits accessibility to certain pores, and equilibrium with synthetic formation fluid mainly drives surface changes.
The hydraulic fracturing stimulation process can alter petrophysical and flow properties of the shale matrix in unconventional reservoirs. These alterations can result from interactions with native and exogenous fluids, and can be detrimental to reservoir productivity. Different experimental procedures have been proposed to study reactive processes and thereby understand the aforementioned interactions. Most published works do not consider the rock initial saturation with formation fluid, or the effect of organic matter (OM). To gain insights into these effects, two reactive experimental sets, differing in experimental conditions, were conducted. In the first set, at 125 ?C and 45 MPa, a stimulation fluid surrogate was put in contact with Baxter Shale samples, previously saturated and equilibrated with synthetic formation fluid. A baseline consisted of exposure to formation fluid exclusively. In the second set, at 0.08 MPa and 25 ?C, contact with stimulation fluid took place as in the first set. Two additional assays in this second set either skipped the initial formation fluid saturation or removed the OM, respectively. Petrophysical properties analyses, focused on the pore architecture, relied on the combined interpretation of gas adsorption and Time-Domain Nuclear Magnetic Resonance (TD-NMR). Results show that the presence of the formation fluid significantly restricts pore space accessibility to the stimulation fluid and mitigates the pore-architecture alteration to the macro-pore region. Mineral dissolution and precipitation dominate over surface or wettability alteration. Next, results suggest that the OM restricts accessibility to some pores. Ultimately, the equilibration process with synthetic formation fluid drives mainly surface alteration, unhindered by OM.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据