SU949608A1 - Oil and gas deposit geochemical location method - Google Patents

Description

The invention relates to geological exploration and may be used, in particular, in the practice of lithogeochemical prospecting for oil and gas deposits prior to setting deep drilling. In addition, it can be used for cele. the correlation of sediments, the dismemberment of sequences that do not contain paleontological remnants, as well as when searching for ore deposits in secondary dispersal halos. A geochemical method is known for prospecting deposits of oil, gas, and bitumoids from specimens selected from a particular grid, which are examined for the content of organometallic compounds in them, which are products of the oxidation of hydrocarbons. It is assumed that a series of metal indicators reaches the earth's surface in the form of metal porphyrins, which, during oxidation, form organics, plastic compounds. These metals include copper, iron, nickel and vanadium. The method involves the treatment of samples with strong acids in the presence of an organic solvent. The resulting mixture is emulated and centrifuged into three phases: solid, acidic, and dissolved, organic. An analysis of the acid phase allows one to obtain anomalous halos, and an organic one - continuous anomalies. Inside the halo 1.. The disadvantage of this method is the complex processing of samples, requiring the use of strong acids in the presence of organic solvents and subsequent chemical analysis, obtained after emulsification and centrifugation of the phases. In addition, the set of elements used, limited only by iron, copper, nickel and vanadium, is not justified and insufficient. As it is known, under the influence of hydrocarbons, the formation forms are changed, and new minerals of a number of other metals, such as manganese, titanium, aluminum, etc., are formed. Perhaps, a more complete account of the complex of neoplasms will lead to more reliable results. There is also known a method for searching oil fields by sampling soil or the subsoil and determining the sulphide content in them. From these data, geochemical maps are made and anomalous areas are recorded, according to which, taking into account the geological structure of the area, aofibi that are most promising in terms of petroleum potential are found. However, this method; as shown by testing it on the actual material of some deposits, in particular, Sev.Varogan in Western Siberia (table), by contrast of sulfide content in the field contour and beyond, gives much less clear results compared to some other minerals of the heavy fraction. The closest to the proposed method is geochemical prospecting, based on the identification of promising for exploration ring-shaped (gaseous) anomalous areas formed as a result of the migration of hydrocarbons from the oil or gas field, which leads, as the authors point out, to deposition at the earth's surface sulfates, soluble compounds, the total content of dissociating salts, inorganic colloids, chlorine, the total content of ions in the sample. The disadvantages of this method are significant lichestvo otde, but it is defined by components that require the use of various techniques and considerable time expenditure Furthermore, unwarranted itself components set kotoryynelz acknowledge successful. As shown by the experimental studies, in some oil and gas bearing areas, for example, for terrigenous sediments of Western Siberia, the determination of indicators such as sulfates — the total amount of dissociating salts, etc. — is practically ineffective because it does not allow anomalous areas to be identified. The aim of the invention is to improve the efficiency of oil and gas exploration. The goal is achieved by the fact that in the method of geochemical search for oil and gas fields, which consists in sampling rocks, determining the content of inernels in them, and selecting anomalous zones, they perform a grain size analysis grains of minerals with a size of 0.25–0.05 mm, of which a heavy fraction with a specific gravity of 2.8–6.0 is obtained by dividing in a heavy liquid. The received interval of the dimensionality of the fraction of particle size analysis is due to what exactly thereto, as is known, the highest content timed ak tsessornyh minerals. The choice of the range of fluctuations in the specific weights of minerals is determined by the fact that it is concentrated suppressively (Solppstv} most often occurs; qi; s; heavy miperalov, including those containing 3 saoyas of the composition, : a hydrocarbon stream. Obi: it contains heavy meta:; loi, recalculated D:: the diagrams for that ;; well, they are used to isolate maps of the most significant fraction of the fraction of fields in the isolates and, according to an abnormal area, d; 1ubine hall: gas and gas. The essence of the method is to select e litolothes tzaznsrodnlh rocks from the selected strata; -gr ;; fn-: 2skogo horizon and carried out 1: from the obtained fractions li k1; artifi cations are taken on a Bbg of 1 g after which the separation is carried out: st: C: a thin liquid with a syllable ele11 :: cm t :: a fraction with a yield of 1; a weight of 2.8-6.0. the quantitative content of the jelly fractions, the construction of the isolators of the map and the town map are abnormally BHCOJVHX. from-ostgolno with fozovyh, polysG KO} -,:.; - grats: - heavy minerals. 3s name ::; Nos. Drunken people contain; and their sragch-geyu with background; witnessing with Malikik migration; south stream; axcj: - ::. H; -c at the depth of the deposits at jr; in natural fluids. If there are no levsdorod clusters, there are no 3 acronome distributions on a flat, and no heavy adherence is observed. Preg-lagaeka-ly crio will allow you to set; livat; Perspectives of specific areas for oil and gas, as well as production of CFU fractions for coal, hydrogen and coal oranges, on the perspective of the B1 and Nsperts: Az.-Tkviae, Study of specific specific material from the Post-Soviet to Zapadnaya region (and experiment -Emtal studies:; odvsrk11: ayu1 efficacy of application; en-ft: e; DLSa of the method in search of oil and gas fields. The method was tested under field conditions. Research, completed in the oil field of the North Variagan in Nizhnevartokom the oil and gas region of Zapadvaoy ibiry made it possible to identify in any of the Orosk Paleogene Paleo- gan — the deepest horizon, the structural geochemical well, 7 times more than the content of the heavy fraction over the deposit: and beyond it 1 and in the Palaeogene / Xeni oil North Variogan field is given in tabl) -:

Heavy content

Geological age

over the deposit

Contrast fraction, kg / t

Lyulinvorska

retinue

(f ,, tt)

Chegansk

retinue

(fj —ZS)

Nekrasovska

retinue

(f ,, nc) As can be seen from the data in the table, the contrast in the distribution of the heavy fraction decreases upward in the Paleogene sediment section, reaching minimum values in the Nekrasov suite in accordance with the decrease in the influence of the hydrocarbon migration flow from the reservoir. The proposed method of geochemical exploration of oil and gas provides compared with the known methods of high performance, expressnet and high efficiency at low cost to carry out prospecting for oil and gas; allows to increase the degree of reliability of assessing the prospects for the oil and gas potential of local areas, to produce a survey of the latter for promising and unpromising before setting deep drilling. These advantages increase the efficiency of geological exploration work oil and gas by reducing the volume of drilling and the total costs of discovery of the field.

7.0

0.9

6.36

1.9

6.20

11.83.

1.1

6.82

Claims (3)

7.32 Formula of the invention A method of geochemical prospecting of oil and gas deposits by sampling rocks, determining their mineral content and isolating anomalous zones, characterized in that, in order to increase the efficiency of the search, a particle-size analysis of the samples is carried out and mineral grains are extracted 0.25-0.05 mm in size, they are divided into heavy liquids to obtain a heavy fraction with a specific gravity of 2.8-6.0 n / m, its content is determined in kg / t, constructed in isolines distribution maps of this fraction, and by the presence of areas with its elevated values E is judged at the depth of the presence of oil and gas. Sources of information taken into account in the examination 1. US patent number 2367592 / CL.23-230, published 1995. 2. US patent number 2348103, CL.23-230, publishedL953. 3. US patent number 3285698, cl. 23-230, published in L973. (prototype).