Title: Predicting the potential for mineral scale precipitation in unconventional reservoirs due to fluid-rock and fluid mixing geochemical reactions

Abstract

Mineral precipitation within hydraulically fractured shale may affect fluid flow pathways and impact longterm hydrocarbon production. The ability to predict geochemical reactions that lead to problematic mineral precipitation will lead to active reservoir management strategies to improve overall production. Using the Marcellus Shale as a case study, a combination of laboratory experiments and reaction path modeling was applied to determine which reactions are likely to occur upon introduction of hydraulic fracturing fluid into the shale reservoir. Experimental results indicate that contact between fracturing fluid and shale will result in dissolution of primary minerals (quartz, feldspars, kaolinite, chlorite, pyrite) and secondary mineral precipitation over time periods of less than one week. Precipitation of barite, Fe-oxides, feldspars, amorphous silica and clay is likely to occur within the reservoir during shut in and early flowback due to mixing between fracturing fluid and reservoir brine as based on modeling saturation indices using experimental fluid data. Reaction path modeling of the experimental scenarios corroborates the specific dissolution and precipitation reactions observed experimentally. Comparison of the results to injected and produced waters from a Marcellus Shale well pad in Greene County, PA, USA, shows that the mineral reactions occur during the hydraulic fracturing, shut in, andmore » early flowback periods. The results presented in this paper demonstrate the value in applying experimental approaches to identify mineral precipitation/dissolution reactions that may significantly impact reservoir performance. The good agreement between geochemical models and experimental results provides confidence that numerical models can be applied to screen the potential fluid-mineral and fluid-mixing reactions in unconventional reservoirs that result in undesired mineral scale precipitation.« less

Authors:

Hakala, Jacqueline Alexandra ^[1]; Paukert Vankeuren, Amelia N. ^[2]; Scheuermann, Peter P. ^[3]; Lopano, Christina ^[1]; Guthrie, Jr., George D. ^[4]

---

+ Show Author Affiliations

1. National Energy Technology Lab. (NETL), Pittsburgh, PA (United States)
2. California State Univ., Sacramento, CA (United States); National Energy Technology Lab. (NETL), Pittsburgh, PA (United States)
3. National Energy Technology Lab. (NETL), Pittsburgh, PA (United States); Univ. of Minnesota, Minneapolis, MN (United States)
4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

Mon Aug 24 00:00:00 EDT 2020

Research Org.:

National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Office of Fossil Energy (FE); USDOE Office of Fossil Energy (FE). Oil and Natural Gas; USDOE Office of Fossil Energy and Carbon Management (FECM)

OSTI Identifier:

1892338

Alternate Identifier(s):

OSTI ID: 1711398; OSTI ID: 1775780

Report Number(s):

LA-UR-20-23831
Journal ID: ISSN 0016-2361

Grant/Contract Number:  

89233218CNA000001

Resource Type:

Accepted Manuscript

Journal Name:

Fuel

Additional Journal Information:

Journal Volume: 284; Journal ID: ISSN 0016-2361

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

58 GEOSCIENCES; Marcellus Shale; mineral scale precipitation; unconventional reservoirs; geochemical reaction path modeling; produced water; fracturing fluid; barite; carbonate; sulfate; aluminosilicate precipitation