Geology. Geophysics. Drilling
GEOLOGY, PETROGEOCHEMISTRY AND ORE POTENTIAL OF CARBONACEOUS DEPOSITS OF CHULAKSAY SUITE (EAST-URALIAN MEGAZONE)
The article gives a detailed description of chulaksay suite, widely represented within the Transuralian uplift. It is shown, that in its composition developed siliceous and quartzitic carbonaceous shales, containing to 1.5 – 2.0 % of graphitic substances. There was described textural and structural features of the rocks, their mineral composition and structural position of carbon, the degree of rock dislocation and metamorphism, substantiated the age of chulaksay suite. It is known that carbonaceous deposits are very informative rocks, which allow to approach the understanding of paleogeographic setting and physico-chemical conditions of accumulation and to elucidate the sources of the demolition of terrigenous material. For this purpose on the basis of chemical analysis of carbonaceous shales and quartzites, petrochemical calculation of modules have built a number of characteristic diagrams, which allowed to solve the question of their belonging to siliceous-carbonaceous formation and low carbon type. It is established that chulaksay suite sediments accumulated in the near-shore environment or at some distance from the shoreline, thus the supply of terrigenous material was minimal. In a row: carbonaceous shales and quartzites – carbonaceous-chlorite-siliceous and carbonaceous-argillaceous-siliceous shales, there is a gradual decrease in maturity of the source rocks. For all of them the source of terrigenous material was mainly ultramafic rocks. The examination of chulaksay suite depositions on noble metals have shown the absence of industrial grade gold and platinum group elements. In the samples we can only note the elevated values of silver approaching weak ore anomalies. The presence among black-shale deposits of numerous acidic and ultramafic dikes allows to hope for a positive outcome with further metallogenic studies.
THE USE OF THERMAL ANALYSIS IN THE EVALUATION OF PROBABLE RESOURCES OF GOLD IN CARBONACEOUS DEPOSITS OF THE BELORETSK METAMORPHIC COMPLEX (SOUTHERN URALS)
The article briefly describes the geological structure of the zonal Beloretsk metamorphic complex; listed suites, which includes carbonaceous deposits, is given all available data sampling of carbonaceous deposits of gold. Based on the thermal method of studying the carbonaceous shales of zigazin-komarov suite established that the exothermic effect in them occurs in the temperature range 630-730 °C, which corresponds to the greenschist and epidote-amphibolite facies of metamorphism. Mapping the temperature distribution within the Beloretsk metamorphic complex, as well as the analysis of patterns of gold-ore objects within it, allowed to bind gold mineralization to a specific temperature interval. This gave the possibility with minimal cost to assess the prospects for carbonaceous deposits of the Beloretsk metamorphic complex on the gold and select a specific area on it prospecting. It is shown that the largest gold mineralizations are confined to tectonically intensively destructed, silicified and sulfidation rocks of black-shale formation, located in an external high-temperature zone of the greenschist facies of metamorphism. The established regularity is very important search value in the further prospecting work on the periphery of the Beloretsk metamorphic dome and confirms correctness of the model of metamorphic-hydrothermal gold mineralization in black-shale strata. In such geological setting was discovered Otnurok gold mineralization in which by test of carbonaceous deposits was identified a layer of ore-bearing rocks with the thickness of six meters. This gold bearing zone is traced in a north-easterly direction for several kilometres along strike in a series of high-grade metal contents, which allowed to calculate probable resources of gold on P2 categories.
The article presents the results of investigations of polymeric reagents production LLP “Cellulose Ethers” (Vladimir), composed of synthetic and natural clay mud of the November oil and gas region of Western Siberia. In particular, we studied experimental and industrial samples karboksimetikrahmala reagents (KMC), experimental and industrial samples and test reagents polysaccharide polymer complex reagent SS.
Samples were submitted to high-viscosity CMC, they lead to an effective increase of the structural, mechanical and rheological properties of the slurry at a concentration of 0.5% and above, but the filtration rate is reduced while not as effective. So KMC sample data were not recommended for drilling the main borehole production casing and completion fluids, and for use in drilling wells under the conductor when the increased viscosity of the solution is required at higher reagent concentrations.
Enterprise TOO “Cellulose Ethers” recommended to finalize the specifications for the Chemproduct and send it to other studies (less viscous) grade CMC.
Additives polysaccharide reagent in the mud do not have an effective impact on the reduction of filtration index. Experimental reagents and industrial samples differ only slightly from each other.
The study sample is an integrated reagent SS of LLP “Cellulose Ethers” (Vladimir) corresponds to advertising data and comparable to previously studied samples of PS NPO “Drilling”. Preparation of the reagent solution polimersolevogo substation reduces the filtration rate to 10-14 cm3 / 30 minutes, but only if strict adherence to the developed technology.
PROSPECTS OF ORE-BEARING CARBONACEOUS DEPOSITS OF AMUR STRATIFORM FIELD ON THE ZINC MINERALIZATION (SOUTHERN URALS)
The paper considers the geological structure of the Amur stratiform zinc deposits in the geological section of which distinguished three strata: molassic, terrigenous-carbonate (flyschoid) and volcanogenic. Describes the parameters of the ore body, its composition, the types of ores and the content of useful components, forms of their presence, reflected the different views of researchers on the history of the formation of the deposit. Special attention in the paper is paid to carbonaceous deposits, which are widely represented in flyschoid stratum. It is shown that black shales belong to low carbon type, as well as terrigenous-carbonaceous and carbonate-carbonaceous formations. Paleogeographic conditions of their deposition corresponded to a shallow basin, within which there where a local depressions. In these local depressions occured the accumulation of pyrite-sphalerite mineralization coming through the narrow channels from the north-west direction (from the Magnitogorsk megazone) with intense volcanism and activities of “black smokers”. In one of these depressions formed the Amur deposit, and the other, situated farther north-east from it – zinc ores the most perspective area within the geological allotment. In the deeper basin depression (located farther south of the deposit) with a higher concentration in the near bottom of the hydrogen sulfide, in the absence of connection with the areas of volcanism, was formed the sediments with pyrite-pyrrhotite mineralization. The north-eastern section was drilled with a series of core holes to test the prospect for zinc ores. Five of the eight exploratory wells have uncovered the ore body with thickness from 6 to 16 meters, which allowed to calculate here inferred resources of zinc by P1 category in the amount of 400 thousand tons.
Results of investigations of physical and chemical properties and the impact on drilling fluid parameters: technical prototype sodium carboxymethylcellulose (Na-CMC) of the brand “Kamtsel-1” manufactured by JSC “Karbokam” in comparison with a reagent Taurus-2; CMC production Novolyalinskogo PPM (Novaya Lyalya Sverdlovsk region); reagent “synthetic adhesive wallpaper” (CSR) household chemical plant “Angarsk petrochemical company” in comparison with a reagent Kem-Pak – karbsimetilirovanny cellulose polymer (manufactured by Kem-Tron, USA) and others.
Kamtsel-1 solution forms amorphous flakes only when mixed with a solution of calcium chloride. Kamtsel reagent-grade 1 corresponds CMC 700, the optimum additive for drilling fluids for drilling a wellbore production tubing up to 0.1% and the solutions used in drilling for conductor – to 0.2-0.25%.
CMC sample is also in line with the brand 600. Optimal additives to drilling fluids for drilling under the production casing comprise 0.05-0.10%, and a jig for drilling – up to 0.2-0.4%. Reagents can be added to drilling fluids in dry form.
CSR solutions are rapidly degraded in the rusty metal container. Additives CSR leads to reduction index filtration of drilling fluids and simultaneously – to improve the structural and rheological properties unlike additives Kem-Pak. Therefore it is necessary to carry out further processing agents, diluents. CSR reagent can be used as a stabilizer in drilling fluids for drilling jig in an amount of 0.5% or more, and when a production tubing drilling – 0.1-0.3%.