..., fluid inclusion, and C-O-Nd isotope data and in situ U-Pb ages of calcite cement to determine the timing and mechanisms of bed-parallel fracture formation. Our findings revealed two generations of bed-parallel fractures: type A and type B fractures. The crystallization age of calcite cement in type...

... in the northern UKSNS. Diagenetic cements (carbonates, sulfates and halite) are common. Most are early and episodic, patchy at local and regional scales, with periods of replacement and dissolution. Consequential fine-scale heterogeneous compaction textures are unrelated to current or maximum burial depths...

... the basin due to paleoenvironmental facies distribution, framework clast composition, and diagenetic processes. Carbonate cements dominate the coarser-grained (fluvial) facies in the northern region. In contrast, gypsum is more conspicuous in the finer-grained (lacustrine and playa lake) facies prevalent...

... are investigated in this work based on oil geochemistry, fluid inclusion analyses, and in situ U-Pb dating of calcite cements. Four charge episodes are identified based on the following: (1) the similar origin but different maturation histories of sampled crude oils; (2) the four distinct fluorescence-color...

...- and fracture-filling cementing saddle dolomite and cementing calcites are recognized in the field. Petrographic studies show the complex diagenetic history of the Samana Suk Formation from near-surface diagenesis, including micritization, neomorphism, and several varieties of dolomites. These varieties...

... operational timescales. Hydrothermal interactions between engineered materials (e.g., bentonite buffers, cements, waste canister materials) and the host rock environment may drive alteration processes that affect the advantageous properties of some barrier materials. However, such alteration will also promote...

... cementation and concurrently with fracturing. The older oil inclusions record the initial oils that served as precursors to the pyrobitumen, while the younger generation was likely formed during oil cracking. Fissure calcites containing primary oil inclusions yield a laser ablation-multicollector-inductively...

... cements. All of these data are integrated by tying the geochemical results to the evolution of the nearby No. 15 fault system and burial/thermal models for key wells. The interpreted seismic data indicate that the No. 15 fault system provided major migration pathways for hydrocarbons. The hydrocarbon...

...Mingqing Huang; Qiwei Zheng; Qingling Liu; Zhong Gao ABSTRACT Waste rocks and tailings are widely applied materials in underground metal mines to backfill mined-out areas. To test the effect of low calcium fly ash on slurry fluidity and long-term strength of cemented paste backfill, orthogonal...

... was found between the geomechanical properties and sedimentary facies in the Montney Formation, in contrast to the behavior of many shale formations, which we attribute to the size and compositional homogeneity of the detrital material comprising the siltstone, and to pervasive cementation at shallow burial...

... contents of carbonate and quartz cements, specific clay mineral types (mixed-layer I/S with Reichweite order of R = 3 and illite), and poor reservoir quality and oil productivity due to the influx of deep inorganic CO 2 dating to circa 65–44 Ma. Petrographic analyses reveal that the K 1 q 4...

... (>5500 m [>18,045 ft]) and has endured a complex diagenetic history. To understand the mechanisms of reservoir formation, we conduct a broad portfolio of geochemical analyses on the calcite cements that fill the pores and fractures in samples retrieved from wells penetrating the Yingshan Formation...

... are very hard and compact, fine-grained, sublihic arenite, and lithic greywacke types and show medium porosity (avg. 11.3%). The reservoir properties of the sandstones of both groups are controlled by various diagenetic alterations like mechanical compaction, cementation, overgrowth, authigenesis of clay...

... of Tipam Sandstone Sample no. Quartz Feldspar Rock Fragments Cement Mica Matrix H.M Q Mu Q Mnu Q P P Ca/Na F K Ig Met Sed C Sil C Fer C Cal Mus Bio M1 11.33 29.67 4.67 7.00 5.33 4.67 7.66 5.67 1.67 8.33 0.00 0.67 4.33 8.00 1.00 M1S 14.67 34.33...

... and resembles the primary matrix (proto-matrix), recrystallized primary matrix (ortho-matrix) and diagenetically produced epi-matrix of Dickinson (1970) . Among cements, silica ( Fig. 5c ) and iron oxide ( Fig. 5c and 6a ) are the two interstitial pore-filling materials found in Kopili sandstones...

...Jiaxin Yu; Kenneth Duffaut; Per Avseth ABSTRACT Quantitative description of the reservoir rock stress sensitivity is critical for seismic modeling and interpretation. Laboratory studies have indicated that the wave velocity of high porosity cemented sandstone is asymmetrically much more sensitive...

... a combination of thin-section petrography, scanning electron microscopy, and mineral segmentation mapping to document rock texture, especially the amount and distribution of quartz and calcite cements. We find that samples dominated by extrabasinal grain components show isolated clusters of intergranular...

... chlorite and heulandite cements. First-generation laumontite cement (60°C–70°C) formed via heulandite transformation during eogenesis. Variable mesogenetic alteration products developed in an organic-CO 2 –based system and mainly included (1) precipitation of pore-filling chlorite, quartz, kaolinite...

... for the precipitation of carbonate cements in adjacent sandstones. Moderate and deep mudstones are mature and able to provide organic acids/CO 2 and other ions to adjacent sandstones. However, shallow mudstones are not mature and have limited mass supply capacity. Subsequent fault movement activates fluid migration...

... to highlight the porosity, which was estimated by eye using transmitted light optical microscopy. This also allowed the microstructure and relative age relationships of fracturing, mineralization and cementation to be determined. Collectively, the basal conglomerates and microbreccias vary significantly...