scholarly journals Chemically Active Elements of Reservoir Quartz Cement Trace Hydrocarbon Migration in the Mahu Sag, Junggar Basin, NW China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Linjun Huang ◽  
Yin Liu ◽  
Baoli Bian ◽  
Yongping Ma ◽  
Hailei Liu ◽  
...  
Keyword(s):  
Organic Geochemistry ◽  
Petroleum Reservoirs ◽  
Junggar Basin ◽  
Northwest China ◽  
Fluid Migration ◽  
Hydrocarbon Migration ◽  
Geochemical Study ◽  
Migration Pathways ◽  
Quartz Grains

Element exchange and enrichment during fluid-rock interactions are common, providing potentially novel proxies to trace hydrocarbon migration in addition to the traditional organic geochemistry tracers. However, the processes, mechanisms, and geological and geochemical fingerprints of these interactions are complex, hampering the applications of hydrocarbon migration tracers. To investigate such interactions, we conducted a petrological, mineralogical, and in situ and bulk geochemical study of authigenic quartz and whole-rock samples from the Mahu Sag, northwestern Junggar Basin, northwest China. We found that dissolution, clay and chlorite formation, and overgrowth occurred on quartz grains in hydrocarbon fluid migration pathways, suggestive of strong fluid-rock interactions. In situ quantitative elemental analysis of quartz grains revealed elemental enrichment (e.g., Mn, Fe, Al, Sr, and W) in quartz overgrowth rims compared with their cores, indicating that migration of hydrocarbon-bearing fluids in reservoirs may promote elemental exchange between fluids and minerals. Whole-rock geochemical analysis showed that decreasing contents of some elements may reflect the direction of hydrocarbon-bearing fluid migration and can be monitored with three geochemical proxies, which are the MnO contents and MnO/Zr and Y/Ho ratios. Our data provide new constraints on fluid-rock interactions in petroleum reservoirs and have implications for using inorganic geochemical methods to trace hydrocarbon migration.

scholarly journals A Method to Simulate the Migration and Accumulation of Hydrocarbon with Analogue Modeling

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jian Cui ◽  
Dong Jia ◽  
Hongbin Wang ◽  
Hongwei Yin ◽  
Yanjun Wang ◽  
...  
Keyword(s):  
Fault Zone ◽  
Oil And Gas ◽  
Ct Scanning ◽  
Northwest China ◽  
Hydrocarbon Migration ◽  
Oil Migration ◽  
Suitable Material ◽  
Long Time ◽  
Fine Quartz ◽  
Migration Pathways

Subsurface migration and accumulation of oil and gas have interested researchers for a long time, but these processes may occur over very long geological periods and are difficult to observe directly, so experimental simulations are warranted. In this study, an experimental method was developed to model hydrocarbon migration in the subsurface structure. Oil migration was simulated in a sandbox model, and industrial CT scanning was used to observe both the internal geometry of the model and the oil migration pathways. In the sandbox model, a NaI solution was used to simulate water, white oil was used to simulate hydrocarbon, and fine quartz sand, glass bead, silica powder, and brown corundum were chosen to represent brittle crust, based on suitable material parameters. A NaI-saturated layered sandbox model was constructed with an along-strike basal discontinuity, which during compression allowed a simple anticline with doubly verging reverse faults to form. Oil was then released continuously at a low rate from an orifice under one limb of the anticline. Initially, the oil migrated vertically through the fault zone until it reached the top of the fault zone; it then migrated laterally along the core of the anticline, saturating a model reservoir by buoyancy and capillary force. This experimental analog helps to explain hydrocarbon migration and accumulation within the Anjihai and Santai anticlines in northwest China.

scholarly journals Two Quantitative Evaluation Methods for Identifying the Migration Pathways in Hydrocarbon Carrier: Application and Comparison

2015 ◽  
Vol 8 (1) ◽  
pp. 172-180 ◽  
Author(s):  
Wang Kun ◽  
Hu Suyun
Keyword(s):  
Junggar Basin ◽  
Fluorescence Analysis ◽  
Well Logging ◽  
Hydrocarbon Exploration ◽  
Source Rocks ◽  
Application Process ◽  
Hydrocarbon Migration ◽  
Basic Work ◽  
Oil Flow ◽  
Migration Pathways

Carrier is an important media linking source rocks and reservoirs. In the past two decades, it is the hot topic for the hydrocarbon geology researchers. Migration pathways in carrier are main space for the hydrocarbon migration. The identification of these pathways has great meaning for the hydrocarbon exploration. In this paper, we define a pathway as a macroscopical area in any shape that relatively apparent hydrocarbon migration exists in the carrier according to some research methods. The sandstone carrier of the Neogene Shawan formation and the unconformity carrier of the Cretaceous being located in the Chepaizi uplift of the Junggar Basin (NW China) are selected as research objects. We used quantitative grain fluorescence analysis (QGF) and effective migration thickness analysis (EMT) to quantitatively study these two kinds of pathways. Migration characteristics of the hydrocarbons are analyzed in single wells and in plane. Analysis results show that evaluation and prediction results from two methods are very similar. This verifies the feasibility of those methods for pathways analysis. Based on the calibration of commercial oil flow well, distribution of migration pathways in plane is obtained, which narrow down the exploration areas. Through practical application, the application process and the considerations of the two methods are discussed and compared. For sandstone carrier, the thickness can be obtained from well logging reports and well logging diagrams. Precondition that the samples collected are located in the carrier interval in QGF analysis is needed. For unconformity carrier, identification of the unconformity surfaces is an important basic work. Increasing the sampling density can reduce the analytical errors caused by the inhomogeneous distribution of oil. EMT method is simple; however, the precondition for application is that the oil in the carrier is not too light and is well preserved in geology history.

Episodic petroleum fluid migration in fault zones of the northwestern Junggar Basin (northwest China): Evidence from hydrocarbon-bearing zoned calcite cement

AAPG Bulletin ◽  
2008 ◽  
Vol 92 (9) ◽  
pp. 1225-1243 ◽  
Author(s):  
Zhijun Jin ◽  
Jian Cao ◽  
Wenxuan Hu ◽  
Yijie Zhang ◽  
Suping Yao ◽  
...  
Keyword(s):  
Junggar Basin ◽  
Northwest China ◽  
Fault Zones ◽  
Fluid Migration ◽  
Calcite Cement ◽  
Petroleum Fluid

scholarly journals Denudation systematics inferred from in situ cosmogenic <sup>10</sup>Be concentrations in fine (50–100 µm) and medium (100–250 µm) sediments of the Var River basin, southern French Alps

2019 ◽  
Vol 7 (4) ◽  
pp. 1059-1074 ◽  
Author(s):  
Apolline Mariotti ◽  
Pierre-Henri Blard ◽  
Julien Charreau ◽  
Carole Petit ◽  
Stéphane Molliex ◽  
...  
Keyword(s):  
Glacial Cycles ◽  
Size Fractions ◽  
French Alps ◽  
Fine Grained ◽  
Denudation Rates ◽  
Variable Morphology ◽  
Cosmogenic 10Be ◽  
The Impact ◽  
Quartz Grains

Abstract. Marine sedimentary archives are well dated and often span several glacial cycles; cosmogenic 10Be concentrations in their detrital quartz grains could thus offer the opportunity to reconstruct a wealth of past denudation rates. However, these archives often comprise sediments much finer (<250 µm) than typically analyzed in 10Be studies, and few studies have measured 10Be concentrations in quartz grains smaller than 100 µm or assessed the impacts of mixing, grain size, and interannual variability on the 10Be concentrations of such fine-grained sediments. Here, we analyzed the in situ cosmogenic 10Be concentrations of quartz grains in the 50–100 and 100–250 µm size fractions of sediments from the Var basin (southern French Alps) to test the reliability of denudation rates derived from 10Be analyses of fine sands. The Var basin has a short transfer zone and highly variable morphology, climate, and geology, and we test the impact of these parameters on the observed 10Be concentrations. Both analyzed size fractions returned similar 10Be concentrations in downstream locations, notably at the Var's outlet, where concentrations ranged from (4.02±0.78)×104 to (4.40±0.64)×104 atoms g−1 of quartz. By comparing expected and observed 10Be concentrations at three major river junctions, we interpret that sediment mixing is efficient throughout the Var basin. We resampled four key locations 1 year later, and despite variable climatic parameters during that period, interannual 10Be concentrations were in agreement within uncertainties, except for one upper subbasin. The 10Be-derived denudation rates of Var subbasins range from 0.10±0.01 to 0.57±0.09 mm yr−1, and spatial variations are primarily controlled by the average subbasin slope. The integrated denudation rate of the entire Var basin is 0.24±0.04 mm yr−1, in agreement with other methods. Our results demonstrate that fine-grained sediments (50–250 µm) may return accurate denudation rates and are thus potentially suitable targets for future 10Be applications, such as studies of paleo-denudation rates using offshore sediments.

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