Effects of smectite on the oil-expulsion efficiency of the Kreyenhagen Shale, San Joaquin Basin, California, based on hydrous-pyrolysis experiments

Lewan, Michael D.; Dolan, Michael P.; Curtis, John B.

doi:10.1306/10091313059

Cited by 41 publications

(21 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The artificial maturation by pyrolysis reduces the TOC of the pyrolysis residues by 5.4% from the immature (EqRo = 0.48%) through the oil window to the overmature (EqRo = 4.05%), which is lower compared with the 30–50% TOC loss for type II kerogen source rocks over a similar maturity range (Baskin, 1997; Lewan et al., 2014). This finding shows that kerogen conversion considerably varies for similar kerogen types from different locations.…”

Section: Resultsmentioning

confidence: 99%

“…Some unstable clay minerals, such as smectite, are removed from crystal water. Under the action of the organic acid generated by the kerogen, the silica is formed by the dissolution of smectite and feldspar and converted into a layer of illite–smectite, illite, and chlorite, along with the formation of nanopores (Chalmers et al., 2012; Chuhan et al., 2000; Lewan et al., 2014). Primary and secondary migration of the generated oils will occur in the oil window stage, with residual oil rich in asphaltene and resin, filling in intra- and intergranular spaces, and plugging the pore throat, resulting in a decrease in shale porosity.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Evolution characteristics and model of nanopore structure and adsorption capacity in organic-rich shale during artificial thermal maturation: A pyrolysis study of the Mesoproterozoic Xiamaling marine shale with type II kerogen from Zhangjiakou, Hebei, China

Wang

Liu

et al. 2018

Energy Exploration & Exploitation

View full text Add to dashboard Cite

Thermal maturity has a considerable impact on hydrocarbon generation, mineral conversion, nanopore structure, and adsorption capacity evolution of shale, but that impact on organic-rich marine shales containing type II kerogen has been rarely subjected to explicit and quantitative characterization. This study aims to obtain information regarding the effects of thermal maturation on organic matter, mineral content, pore structure, and adsorption capacity evolution of marine shale. Mesoproterozoic Xiamaling immaturity marine oil shale with type II kerogen in Zhangjiakou of Hebei, China, was chosen for anhydrous pyrolysis to simulate the maturation process. With increasing simulation temperature, hydrocarbon generation and mineral transformation promote the formation, development, and evolution of pores in the shale. The original and simulated samples consist of closed microspores and one-end closed pores of the slit throat, all-opened wedge-shaped capillaries, and fractured or lamellar pores, which are related to the plate particles of clay. The increase in maturity can promote the formation and development of pores in the shale. Heating can also promote the accumulation, formation, and development of pores, leading to a large pore volume and surface area. The temperature increase can promote the development of pore volume and surface area of 1–10 and 40-nm diameter pores. The formation and development of pore volume and surface area of 1–10 nm diameter pores are more substantial than that of 40-nm diameter pores. The pore structure evolution of the sample can be divided into pore adjustment (T < 350°C, EqRo < 0.86%), development (350°C < T < 650°C, 0.86% < EqRo < 3.28%), and conversion or destruction stages (T > 650°C, EqRo > 3.28%). Along with the increase in maturity, the methane adsorption content decreases in the initial simulation stage, increases in the middle simulation stage, and reaches the maximum value at 650°C, after which it gradually decreases. A general evolution model is proposed by combining the nanopore structure and the adsorption capacity evolution characteristics of the oil shale.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Evolution characteristics and model of nanopore structure and adsorption capacity in organic-rich shale during artificial thermal maturation: A pyrolysis study of the Mesoproterozoic Xiamaling marine shale with type II kerogen from Zhangjiakou, Hebei, China

Wang

Liu

et al. 2018

Energy Exploration & Exploitation

View full text Add to dashboard Cite

show abstract

“…Differences in pyrolysate compositions have been attributed to the mineral matrix effect. This effect occurs in many open-and closed-system pyrolysis experiments including Rock-Eval (Espitalie et al 1980(Espitalie et al , 1984Senga-Makadi 1982), pyrolysis-GC (Horsfield & Douglas 1980;Karabakan & Yürüm 1998), bulk kinetics determination (Dembicki 1992;Burnham 1994;Pelet 1994;Dessort et al 1997) and hydrocarbon expulsion efficiency calculations (Lewan et al 2014), and is brought about by sorption followed by catalytic thermal degradation. Because of their high surface area (Sing 1985), clay minerals (especially smectite) have the ability to strongly adsorb pyrolysate (Espitalie et al 1980(Espitalie et al , 1984, especially the heavy compounds (Katz 1983).…”

Section: Comparison and Discussionmentioning

confidence: 99%

“…A very high TOC or low clay content can decrease or prevent the effect (Reynolds et al 1995). Tannenbaum & Kaplan (1985) and Lewan et al (2014) also reported that the existence of water in the pyrolysis experiments can hinder the excessive formation of coke and catalysing function of clay minerals. However, because the TOC content of Bowland Shale ranges from 1.3 to 9.1% (Gross et al 2014), clay contents are considered to be medium to high (USEIA 2011) and all pyrolysis experiments employed here are anhydrous systems, the mineral matrix effect is probably inevitable in the Bowland Shale pyrolysis experiments (except in those samples with TOC content higher than 6%).…”

Section: Comparison and Discussionmentioning

confidence: 99%

On the primary and secondary petroleum generating characteristics of the Bowland Shale, northern England

Yang

Horsfield

Mahlstedt

et al. 2015

JGS

View full text Add to dashboard Cite

The Carboniferous Bowland Shale of northern England has drawn considerable attention because it has been estimated to have 1329 trillion cubic feet hydrocarbons in-place (gas and liquids) resource potential (Andrews 2013). Here we report on the oil and gas generation characteristics of three selected Bowland Shale whole-rock samples taken from cores and their respective kerogen concentrates. Compositional kinetics and phase properties of the primary and secondary fluids were calculated through the PhaseKinetics and GOR-Fit approaches and PVT modelling software. The three Bowland Shale samples contain immature, marine type II kerogen. Pyrolysate compositions imply primary generation of paraffinic–naphthenic–aromatic (PNA) oil with low contents of wax and sulphur. Bulk kinetic parameters have many similarities to those of productive American Palaeozoic marine shale plays. The secondary gas generation potential of Bowland Shale is greater than the primary gas potential although it requires a 10 kcal mol −1 higher activation energy to achieve peak production. Primary oil, primary gas and secondary gas reach their maximum generation at 137, 150 and 200°C respectively for a 3°C Ma −1 heating rate. Different driving forces of expulsion including the generation of hydrocarbon and overpressure caused by phase separation during sequential periods of subsidence and uplift could be inferred.

show abstract

“…As a self-generation and self-accumulation system, a variety of reactions between fluid and rock fabrics take place in shale reservoir during thermal maturation. Mineral composition as well as rock texture is involved in the processes of hydrocarbon generation and retention in shales, physically and chemically (Rahman et al 2018;Shao et al 2018a, b;Lewan et al 2014). Thermochemical sulfate reduction (TSR) is a thermally driven reaction between hydrocarbons and sulfates and has been reported to be responsible for high H 2 S concentrations in many petroleum accumulations (Krouse et al 1988;Orr 1974;Worden et al 1995;Cross et al 2004).…”

Section: Loss Of Hydrocarbon Yields During Thermal Maturationmentioning

confidence: 99%

Hydrocarbon generation from lacustrine shales with retained oil during thermal maturation

Shao

Pang

et al. 2020

Pet. Sci.

View full text Add to dashboard Cite

Thermal maturation in the shale oil/gas system is inherently complex due to the competitive interplays between hydrocarbon generation and retention processes. To study hydrocarbon generation characteristics from shales within different stages of thermal maturation under the influence of retained oil, we performed Micro-Scale Sealed Vessels (MSSV) pyrolysis on a set of artificially matured lacustrine shale samples from the Shahejie Formation in the Dongpu Depression in Bohai Bay Basin, China. Experimental results show that hydrocarbon yields of shale samples with or without retained oil at various thermal maturities follow different evolution paths. Heavy components (C 15+) in samples crack at high temperatures and generally follow a sequence, where they first transform into C 6-14 then to C 2-5 and C 1. Methane accounts for most of the gaseous products at high temperatures in all samples, with different origins. The cracking of C 2-5 is the main methane-generating process in samples with retained oil, whereas the source of methane in samples without retained oil is kerogen. In the studied shales, retained oils at early-mature stage retard the transformation of liquid to gaseous hydrocarbon and prompt the cracking of C 2-5 to C 1 to some extent. TSR reaction related to gypsum in the studied samples is the primary reason that can explain the loss of hydrocarbon yields, especially at high temperatures. In addition, transformation of volatile hydrocarbons to gas and coke also accounts for the loss of generated hydrocarbon, as a secondary factor.

show abstract

Effects of smectite on the oil-expulsion efficiency of the Kreyenhagen Shale, San Joaquin Basin, California, based on hydrous-pyrolysis experiments

Cited by 41 publications

References 48 publications

Evolution characteristics and model of nanopore structure and adsorption capacity in organic-rich shale during artificial thermal maturation: A pyrolysis study of the Mesoproterozoic Xiamaling marine shale with type II kerogen from Zhangjiakou, Hebei, China

Evolution characteristics and model of nanopore structure and adsorption capacity in organic-rich shale during artificial thermal maturation: A pyrolysis study of the Mesoproterozoic Xiamaling marine shale with type II kerogen from Zhangjiakou, Hebei, China

On the primary and secondary petroleum generating characteristics of the Bowland Shale, northern England

Hydrocarbon generation from lacustrine shales with retained oil during thermal maturation

Contact Info

Product

Resources

About