Jixi Basin Research Articles

Geochemical Characteristics of Lower Cretaceous Chengzihe Formation Mudstones in the Jixi Basin, China: Implications for Provenance, Paleoenvironment and Tectonic Setting

Geochemical Characteristics of Lower Cretaceous Chengzihe Formation Mudstones in the Jixi Basin, China: Implications for Provenance, Paleoenvironment and Tectonic Setting

Abnormal Characteristics of Component Concentrations in Near-Surface Soil Gas over Abandoned Gobs: A Case Study in Jixi Basin, China

Abnormal Characteristics of Component Concentrations in Near-Surface Soil Gas over Abandoned Gobs: A Case Study in Jixi Basin, China

A marine transgressive cycle driven by the dynamics of the Paleo-Pacific subduction: Insights from structural architecture and kinematics of the Jixi basin, NE China

A marine transgressive cycle driven by the dynamics of the Paleo-Pacific subduction: Insights from structural architecture and kinematics of the Jixi basin, NE China

Pore-fracture and permeability heterogeneity of different marcolithotypes of medium-rank coals in Jixi Basin, China

The pore-fracture system of different marcolithotypes (bright, semi-bright, semi-dull and dull coals) is quite different, which has great influences on coalbed methane (CBM) exploitation. Here the optical microscope (OM), scanning electron microscope (SEM), mercury intrusion porosimetry (MIP), low-temperature nitrogen adsorption (LTND) and X-ray computed tomography (X-CT) are performed on different marcolithotype coals from Jixi Basin. From bright coals to dull coals, “ink bottle” shaped pores account for a gradually increasing proportion of the transition pores, but contribute fewer mesopores. The results of LTND and MIP indicate that bright coals have the poorest mercury removal efficiency and lowest BET specific surface area, while the opposite appears to be the case for dull coals. According to the pore size distribution based on LTND and MIP, from bright coal, semi-bright coal, semi-dull coal to dull coal, the total pore volume gradually decreases, with the proportion of macropore volume occupying 76.2%, 5.1%, 3.7% and 1.7%, respectively. On the basis of the 3D reconstruction of the pore-fracture system obtained from X-CT, the bright coal is characterized by high connected porosity and total porosity, presenting the best pore-fracture system. The pore network of bright coal is three-way interconnected with the largest number of pores and the shortest and densest throats, which facilitates the communication of fluids between the pores. In contrast, dull coals with a unidirectionally connected pore network model, fewer pores and sparse throats, have a poor seepage capacity. In addition, the X-CT seepage simulation results and the gas permeability results confirm the superiority of the pore-fracture system in bright coals.

Experimental Investigation of Pore Characteristics and Permeability in Coal-Measure Sandstones in Jixi Basin, China

The research of pore and permeability characteristics of tight sandstone reservoirs in coal-measure is critical for coal-measure gas development. In this study, the pore systems of tight sandstones were studied based on low-field nuclear magnetic resonance (LF-NMR) data. The permeability of tight sandstones was obtained by the tester based on the pulse transient method. The permeability variation with the effective stress, grains, and pore characteristics was analyzed. The results show that the tight sandstone reservoirs in the coal-measure have low total porosity (2.80–4.14%), low effective porosity (0.51–1.56%), and low permeability (0.351 × 10−6–13.910 × 10−6 um2). LF-NMR T2 spectra of the testing sandstones show that the micropores are the most developed, but most of the micropores are immovable pores. The pore characteristics are significantly affected by the grain size of sandstones. The pore connectivity ranks from good to poor with decreasing sandstone particle size. The total porosity and effective porosity increase with the grain size. There is a near-linear negative relationship between permeability and effective stress when the effective stress is between 405 psi and 808 psi. The greater the number of movable pores and the larger the effective porosity, the bigger the permeability of the sandstone. The effective porosity of sandstones is a sensitive indicator for evaluating the permeability of tight sandstone reservoirs. The stress sensitivity coefficient of permeability (Ss) increases with the increase of the effective stress. The sandstone with lower permeability, smaller effective porosity, and finer grains has a higher Ss. The particle size of sandstone from coal-measure has a great influence on both permeability and Ss. The findings will provide a better understanding of the characterization of pore structure and permeability in the process the coal-measure gas extraction, which is useful for the efficient development of coal-measure gas.

New zircon U–Pb age of the Didao Formation in Jixi Basin and its significance for the geology and paleogeography in Jixi and eastern Heilongjiang region in the Early Cretaceous

The coal-bearing Jixi Basin of Heilongjiang is a unique Cretaceous basin in Northeast China, depositing non-marine alternated marine strata during transgressions in the Early Cretaceous. However, the ages of the Didao-, Chengzihe- and Muling formations and their relationships to transgressions and regressions have been under debate mainly due to a lack of radiometric constraints and comprehensive study of the fossils. The authors report results of new LA-ICP-MS zircon dating from the tuff of the Didao Formation in its type section (131.5 ± 1.4 Ma), which is the oldest isotopic dating data reported for the Early Cretaceous in eastern NE China. This dating result shows the earliest known volcanic activity happened in the Hauterivian stage, which implies the initial rifting of the Jixi Basin probably in the Hauterivian and caused the first sea staged regression eastward or northeastward in Jixi Basin during the Early Cretaceous. Additionally, a comprehensive study of the plant and dinoflagellate fossils, new dating, and the regional paleogeographic characteristics, indicates a Valanginian-Hauterivian age for the Didao Formation, improving the stratigraphic study of the Didao Formation in accuracy. Moreover, according to the dating in the eastern Northeast China, the four volcanic stages in this region during the Early Cretaceous can be recognized as follows (i) the Didao volcanic stage (ca. 130–132 Ma); (ii) Early Chengzihe-Boli volcanic stage (ca. 119–126 Ma); (iii) Late Chengzihe-Muling volcanic stage (ca. 110–117 Ma); (iv) the Dongshan volcanic stage (ca. 101–108 Ma).

Industrial production of unconventional gas in coal-measure of Well HJD1 in Jixi Basin, Eastern Heilongjiang Province, China

Industrial production of unconventional gas in coal-measure of Well HJD1 in Jixi Basin, Eastern Heilongjiang Province, China

Pore-Fracture Multi-Scale Characterizations of Different Marcolithotypes of Medium-Rank Coals in Jixi Basin, China

Pore-Fracture Multi-Scale Characterizations of Different Marcolithotypes of Medium-Rank Coals in Jixi Basin, China

Geochemical characteristics of mudstones from the lower cretaceous strata of the Jixi Basin, NE China: Implications for organic matter enrichment

Organic-rich mudstone, whose formation and accumulation are strongly related to the depositional environment, is a potential source of natural gas. Here, geochemical tests (including total organic carbon (TOC), rock pyrolysis, X-ray diffraction (XRD), and main and trace element analyses) were carried out on mudstone samples from two boreholes in the Jixi Basin to reveal the paleoenvironment and its control on organic matter enrichment. The results show that type III kerogen dominated and that all samples entered the maturity stage with good hydrocarbon generation potential. Generally, the TOC content tended to increase with increasing depth, and the mudstone in the middle (K1ch2) and lower (K1ch1) segments of the Chengzihe Formation was characterized by good quality with TOC > 2.5%. In the Jixi Basin, two common types of mudstones (silica-dominated mudstone and silica-rich argillaceous mudstone) were mainly composed of quartz and clay minerals. These mudstones were rich in Na2O, MnO and several trace elements (e.g., Zn, Mo, and Bi) and depleted in other elements (e.g., MgO, CaO, Cr, Co, and Ni). The rare earth element and yttrium (REY) distribution patterns normalized by North American shale compositions (NASC) were flat, with slight negative Ce and Eu anomalies. The ratios of Sr/Cu, Rb/Sr, Sr/Ba and V/(V + Ni) in mudstones indicated a warm-humid paleoclimate, a suboxic environment and a marine-continental transitional fresh-brackish water mass. From the K1ch1 to Muling Formation (K1m), although the paleoclimate was more arid and paleosalinity increased gradually, depositional environments were in fresh-brackish water. The paleoclimate and clastic influx are the keys to controlling the enrichment of organic matter. The paleoclimate indirectly affects the preservation of organic matter by influencing the aquatic environment and controlling the level of paleoproductivity, while the strong clastic influx rate directly dilutes organic matter preservation.

Timing of the late Jehol Biota: New geochronometric constraints from the Jixi Basin, NE China

The Jehol Biota is a world-famous Early Cretaceous terrestrial ecosystem in East Asia and has revealed exceptionally well–preserved fossils which provide significant insights into the origin and evolution of birds and feathers, and the early diversifications of mammals and angiosperms. After the long-lived controversies over the timing of the biota varying from Late Jurassic to Early Cretaceous in last century, the lifespan of the early-middle Jehol Biota has been precisely dated from Barremian to early Aptian (ca. 131–120Ma) by a series of recent radiometric analyses. However, few well–constrained ages are available for the late Jehol Biota, hindering our complete understanding of the evolutionary history of the terrestrial ecosystem. Alternating marine and non-marine deposits of the Chengzihe Formation in eastern Heilongjiang have yielded a non-marine bivalve assemblage of the Jehol Biota, basal angiosperms, and Cretaceous marine index bivalves, which collectively offer crucial and indisputable clues against the prevailing Jurassic time of the biota since 1990s. Here we present the first discovery of tephra layers from the Chengzihe Formation, dated by zircon U-Pb geochronology as ca. 116–111Ma, providing the first quantitative age calibration for the early angiosperms and the Jehol bivalve assemblage. Therefore, we demonstrate that the duration of the Jehol Biota extends to late Aptian–early Albian, approximately 4–9Myr younger than the currently accepted age limits.

Early Cretaceous ammonites from eastern Heilongjiang, northeastern China, and their chronostratigraphical significance

A low-diversity ammonite fauna is described from the Qihulin Formation of the dominantly non-marine Longzhaogou Group exposed in Mishan and Hulin counties in eastern Heilongjiang, northeastern China. The fauna consists predominantly of Pseudohaploceras? cf. nipponicum Shimizu, 1931, and Pseudohaploceras? peideense (Liang, 1982), with subordinate Eogaudryceras (Eogaudryceras) cf. yunshanense (Liang, 1982). The occurrence of Pseudohaploceras? and previously reported bivalves suggest an early Aptian age for the Qihulin Formation. The early Aptian transgression advanced from the east across the Hulin and Mishan area into the Jixi Basin and resulted in the deposition of the marine beds of the Qihulin and lower Chengzihe formations. The Qihulin Formation can be correlated with the lower part of the Chengzihe Formation.

Micro/Nano-Pore Characterization of Coalbed Methane Reservoir in Jixi Basin, Northeast China

Micro/Nano-Pore Characterization of Coalbed Methane Reservoir in Jixi Basin, Northeast China

Age and palynological characteristic of the Dongning Formation (Eastern Heilongjiang, China)

The taxonomic composition of the palynological assemblage of the Dongning Formation is supplemented. The palynological assemblage corresponds to those from the Lipovtsy Formation (Aptian) in the Razdolnaya Basin of Primorye (Russia) and the Muling Formation (Aptian) in the Jixi Basin of eastern Heilongjiang (China). It is found that the age of the Dongning Formation is Aptian. The palynological assemblage is characterized by dominance of spores of Gleicheniaceae; they are accompanied by spores of Cyatheaceae. The most important feature of the palynological assemblage of the Dongning Formation is the presence of angiosperm pollen (Tricolpites sp., T. micromunus, T. vulgaris, Retitricolpites georgiensis, R. vulgaris, Clavatipollenites hughesii, Quercites sparsus, Fraxiniopollenites variabilis).

Fossil Liverworts from the Lower Cretaceous Huolinhe Formation in Inner Mongolia, China

AbstractA new genus and species, Rebouliothallus huolinhensis sp. nov., and two uncertain species, Ricciopsis sp. and Hepaticites sp., are described. The fossils were collected from the Lower Cretaceous Huolinhe Formation of Huolinhe Basin, northeastern China. The new genus Rebouliothallus was established in the Aytoniaceae family of Marchantiales. Rebouliothallus huolinhensis appears to be quite similar to species of the extant genus Reboulia Raddi. The species is characterized by the relatively large ventral scales. Ventral scales are large, imbricate and arranged in two rows on the ventral surface. Rhizoids are either pegged or smooth. Ricciopsis sp. is characterized by the rosette‐forming thallus. Hepaticites sp. shows some similarities to liverworts. Of the forty‐nine Early Cretaceous floras of China, only two floras, one from the Huolinhe basin, Inner Mongolia and the other from the Jixi Basin, Heilongjiang Province, contain fossil liverworts. The rare fossil liverwort records in the Early Cretaceous floras of China may be the result of taphonomic bias.

Main Controlling Factors of CMB Reservoir in Northeast China: Taking Jixi Basin as An Example

Main Controlling Factors of CMB Reservoir in Northeast China: Taking Jixi Basin as An Example

Jixi Basin CBM Accumulation Condition Analysis

Heilongjiang Jixi Basin is one of the important coal basins, and the CBM exploration is still in its infancy. This study shows that Jixi Basin is large in number of plies, thin in depth, poor continuity; the types of coal give priority to gas coal and coking coal, reaching the limits of angry thermo genic gas, coal seam gas with a large amount of gas supply is sufficient. In the southern basin, coal mainly developed in the range of 300~1200m, burial depth is moderate, and the dip is small, it is more favorable compared with the north.

Analogy Analysis of Coalbed Methane Reservoir-Forming Conditions in Jixi Basin

Based on coalbed methane geology theory, make use of coal and oil drilling data, from both of the coal reservoir characteristics and conservation conditions, Through comparative analysis of a number of geological factors of coalbed thickness, burial depth, metamorphic grade, gas content, roof and floor lithology, dip angle, etc, and found that there are many similarities between Jixi Basin and Black Warrior Basin in the United States of coalbed methane reservoir conditions. Compared to Black Warrior Basin, the advantages of Jixi Basin are that the coal metamorphism degree is high, the tired and single coalbed are thick, the closeness of roof and floor are good, the fault development and coalbed gas content are similar to it; the disadvantages of Jixi Basin are that the formation dip angle is large, the pressure gradient and permeability are small.

Favorable Areas Prediction in Jixi Basin

Based on coalbed methane geology theory, make use of coal and oil drilling data, from both of the coal reservoir characteristics and conservation conditions, Through comparative analysis of a number of geological factors of coalbed thickness, burial depth, metamorphic grade, gas content, roof and floor lithology, dip angle, etc, and found that there are many similarities between Jixi Basin and Black Warrior Basin in the United States of coalbed methane reservoir conditions. Furthermore, referred the domestic and abroad coalbed methane mining experience, a number of geological factors of Jixi Basin were made grading evaluation, optimized favorable blocks, and we found that the favorable coalbed methane target area are the F and H in the south of the basin, and the F block can be used as the preferred favorable coal exploration area.

CBM Exploration Prospects Analysis in Northeastern Chian – In Jixi Basin as an Example

The northeast part of China has rich coal resources and many coal basins. It has good prospects for CBM exploration. By drilling data analysis, this article evaluates coal seam characteristics and predicts seam thickness and spatial distribution of Chengzhihe formation. Jixi Basin has wide coal distribution, high seam gas content, good capping conditions, through a comprehensive analysis of factors such as coal seam thickness, depth and degree of metamorphism. the south of Jixi Basin is a key exploration area for CBM exploration and development in the northeast part of China.

The Analysis and Analogy Evaluation of the Forming Conditions in Typical Coal-Bearing Basins of Outer Daqing

Jixi BasinHegang Basin and Boli basin are major coal mining areas of the Daqing Exploration Area. They are rich in coal resources. In this paper, through analyzing the main controlling factors of the enrichment and reservoiring of the CBM, and the analogy of geological conditions between basins in studying area and other basins, the coalbed methane exploration and development is very successful. Basing on this, the article chooses Fuxin basin and Black Warrior basin as contrast basins to predict the resource by analogy, as the two basins have the similar geological conditions with the basins in studying area. The results show that Jixi basin has the highest total CBM resource, which is as much as 1672.07×108m3. And Hegang basin has the highest score of the potential enrichment of resource, so these two are preferred profitable exploration basins.