A Technology of Hydrocarbon Fluid Production Intensification by Productive Stratum Drainage Zone Reaming

The paper proposes a new technology for fluid production intensification, in particular hydrocarbons, which is implemented via significant increasing of the local wellbore diameter in the interval, where the productive stratum is present. The proposed technology improves the well productivity by increasing the filtration surface area and opening new channels for filtering fluids into the well. The innovative, technical idea is to drill large diameter circular recesses in planes perpendicular to the well axis. After that, the rock mass located between the circular recesses are destroyed by applying static or dynamic axial loads. The required value of the axial force is provided by the weight of the standard drilling tool. As a result of the study, the analytical relations to specify the admissible radius of circular recesses and admissible thickness of rock mass between two adjacent circular recesses from the condition of safe operation are obtained. The numerical analysis carried out for typical reservoir rocks substantiated the possibility of well diameter local reaming twenty times. A special tool for circular recess drilling is developed and the principle of its operation is described. The advantage of the proposed approaches is the low energy consumption for well diameter reaming. Our technology will have special economic expediency for the intensification of production from hydrodynamically imperfect wells and under the condition of fluid filtration according to the expressed nonlinear law.

Study of zeolite-containing silicon rocks of Dagestan for obtaining a mineral additive to cement

Siliceous-carbonate rocks are widespread on the territory of the Republic of Dagestan, in which the total content of zeolites and opal-cristobalite-tridymite phase (OCT) exceeds 45 %, and the content of calcite is above 30 %. The rocks, composing a productive stratum (at least, most of it), lithologically correspond to opoka-like and highly siliceous limestones, zeolite-containing (10–15 %) and zeolite (40 % or more), weakly quartz and weakly clayey. However, they are distinguished from pure limestones by a low value of actual calcite part — often less than 50 %. Therefore, in this case, the section of the productive strata is defined as «folded by siliceous-carbonate zeolite-containing rocks.» Such rocks, in accordance with the results of laboratory and technological study, are considered as raw materials for the production of building materials. Zeolite-containing rocks are suitable for use as an additive in Portland cement, which will save cement clinker in the production process and improve the quality of cement. Prospecting works for zeolites and zeolite-containing rocks in the Levashinskaya (Levashinsky district) and Rubaschayskaya (Tabasaran and Kaitagsky districts) areas of Mountainous Dagestan were carried out by the non-metallic party of JSC Sevkavgeologiya in 2007–2009. The resources of siliceous zeolite-containing rocks are in the P1 category — 49.308 million tons, in the P2 category — 69.470 million tons. The predicted resources, their laboratory and technological properties (physicochemical, chemical, technological) indicate the possibility of creating a solid mineral resource base and construction of large complexes for the extraction and processing of zeolites and siliceous rocks in Levashinsky (Levoberezhny and Pravoberezhny areas) and Tabasaran (Dyubek area) regions of the Republic of Dagestan.

A probabilistic and statistical model of rock deformation

A new approach to the study of strength characteristics of the rocks on the basis of probabilistic and statistical models of the deformation processes (models of dilatancy initiation processes) under conditions of uncertainty is presented. The main purpose of the study is to create geological and mathematical tools, which could be used to study the development of volumetric deformation (dilatancy, disintegration) of reservoirs at a constant tension, acting on the array. The information and analytical basis of the performed study consists of methods of mathematical statistics and probability theory and the sedimentary rocks research methods. The probabilistic-statistical approach is formed in the study of deformation processes of the productive stratum structure, taking into account the degree of heterogeneity of the reservoirs. The obtained analytical expressions allow us to determine the moment of the beginning of the volumetric deformation process (dilatancy, disintegration) in the rock, similar to the identification of the bifurcation point in the development of geological and dynamic systems

Development of oil–and–gas science and practice in the 21st century

An oil deposit is a «living» fluid–rock system capable of self–regulation. Rehabilitation cycles and soft, sparing methods of improving oil recovery are the basis of a long life of an oilfield. This fluid–rock system (oil deposit) must be studied in detail with the use of special smart autonomous sensors located directly inside the productive stratum (focus). Many researchers note upstream and midstream uncertainties and risks.

RESULTS OF PETROPHYSICAL STUDIES OF THE PRODUCTIVE STRATUM DEPOSITS OF THE BAKU ARCHIPELAGO NORTHERN OIL AND GAS BEARING AREAS

The complex results of petrophysical testing of rocks, taken from prospecting-development wells of Duvanni-deniz, Sangachal-deniz, Bulla-deniz, Garasu and etc. areas, where the sediments of productive stratum are widely expanded, have been given. Average values of granulometric composition of rocks of productive unit of the above areas by the section have been recounted. The problem of dependence of permeability on porosity and depth was solved. Dependence between physical parameters for the individual kinds of rocks, dependence between physical properties and material structures are established. The results of various petrophysical research methods show that the filtration capacitance properties, in general, deteriorate with depth. However, in certain cases, in clay and carbonate rocks, reservoir properties can improve, due to the appearance of secondary porosity under relatively stringent thermobaric conditions. The histograms, which consist of average values of granulometric composition of productive stratum rocks when crossing some places of archipelago are constructed, the problems of dependence of permeability on porosity and depth were solved. The researches showed, that the physical process of the same- named and same-aged features rocks change in the result of geological-physical processes, getting different values. It's noticed, that the porosity and permeability are increasing from north-west to south-east by changing lithological composition.

Methodical and Applied Aspects of Hydrodynamic Modeling of Options of Mining Operation Curtailment

The physicomathematical conjugation of filtration models of a flooded and an adjacent mine is carried out with a justification of methodological principles of analysis and prediction of a technogenic mode of groundwater in conditions of operation and flooding of a mine field. The identity of models and real objects is established as a result of solving a series of inverse problems and is confirmed by a water balance discrepancy of 0.003%, the convergence of water inflows in separate layers with a deviation of 5 – 12.5% and the coincidence of groundwater surface levels on models and data of a mode network. According to results of predictive solutions, it is established that dynamics of flooding of a rock massif within old stopes are more intensive than the restoration of a level of groundwater in a mine shaft. The options of technical solutions for curtailment of mining operations are justified, the ecological risks and costs of which can be optimized by constructing a water intake of technical (or drinking) water in the productive stratum of riverbed sandstones, as well as equipment for geocirculation heat supply systems using the capacitive resource of a flooded mine field.

ASSESSMENT OF POSSIBLE IN-SITU FORMATION OF HYDRATE DURING GAS PRODUCTION FOR THE CONDITIONS OF THEGAS FIELD YUZNO-RUSSKOE

To assess the possibility of hydrate formation during gas production a mathematical model has been developed. This model takes into account the real properties of gas, the adiabatic and throttling effects. Also, the computer program has been written, which allows calculating the distributions of the main parameters in the productive stratum. The analysis of the bottomhole pressure, permeability and porosity influence on the character of distribution of temperature and pressure in the reservoir has been carried out.

SOME SPECIFIC FEATURES OF MARGINAL WELLS COMPLETION

The article presents the generalized experience of marginal oil wells completion. A technology was developed which allows maintaining the stability of the drilled borehole walls stability at the expense of capillary imbibition of the productive stratum with the injected special composition developed by the authors based on the professor Ya-gafarov’s study results.

STRUCTURE AND DYNAMICS OF SEDIMENTATION OF PRODUCTIVE STRATUM BS10-11 IN THE SOUTH-YAGUNSK FIELD

The article presents the analysis of the results of the correlation of sections by twenty-three profiles located across the strike of the ancient coastline along the regression of Neocomian basin, i.e. in the latitudinal direction. The structure and dynamics of sedimentation of the productive stratum BS-10 in the South-Yagunsk field are identified.