Застосування скінчено-елементно-різницевого методу для моделювання анізотропних фільтраційних процесів

We consider modeling and geophysical interpretation of the obtained results in the oil and gas production problems in anisotropic reservoirs. For solving these practical problems, we use combined finite element-differences method of resolving anisotropic piezoconductivity problem with calculation of heterogeneous filtration parameters distribution of oil and gas productive reservoirs and oil-gas penetration conditions in the borders of investigating areas. We have defined that the anisotropy of oil and gas permeability in the far zone of the well has a greater effect on the filtration processes around the well and, accordingly, on the producing of the raw materials than the anisotropy of permeability in the near zone of the well. We have shown that the intensity of filtration processes in anisotropic reservoirs near the acting well depends significantly on the shear permeability and to a lesser extent on the axial permeability of the corresponding phase. Therefore, for the effective using of anisotropic reservoirs, it is necessary to place production wells in local areas with relatively low anisotropy of permeability of the reservoir, especially to avoid places with shear anisotropy. Pages of the article in the issue: 63 - 66 Language of the article: UkrainianРозглянуто моделювання і геофізичну інтерпретацію у практиці нафто-газовидобування у анізотропних пластах. Для вирішення цих прикладних проблем застосовано комбінований скінчено-елементно-різницевий метод розв’язання анізотропної задачі п’єзопровідності з урахуванням неоднорідного розподілу фільтраційних параметрів нафто-газоносних пластів та умов інфільтрації нафти і газу на границях досліджуваної області

On the influence of large-scale mantle irregularities on the daily Liava numbers

On the base of original combined method, allowing to superpose analytical advantages of the Sasao, Okubo, Saito approach with computer possibilities of the finite element method it was carried out evaluation of influence of sub horizontal large-scale mantle heterogeneities about some thousands km long on the Love and Shida numbers of the second order for diurnal tides. It was shown that pre-sence of such mantle heterogeneities non linearly influences on the earth tidal parameters. And this influence on the diurnal Love and Shida numbers of the second order can reach a few percentages

Application of the finite element-differences method for modeling of filtration processes

We consider modeling and geophysical interpretation of the obtained results in the oil and gas production problems. For solving these practical problems, we use combined finite element-differences method of resolving piezoconductivity problem with calculation of heterogeneous filtration parameters distribution of oil and gas productive reservoirs and oil-gas penetration conditions in the borders of the reservoirs. At that, we consider the main factors, which influence on the intensity of filtration processes near oil production well and gas production well respectively. These factors are important for effective supporting in practice high level of the oil and gas production. On the base of computer modeling, we have showed that intensity of filtration process near the acting oil and gas production wells mainly depends on oil phase and respectively gas phase permeability, as in close zone of well acting so in remote zone. The viscosity and reservoir porosity parameters in close and remote zones of the well action have little direct effect on filtration process near the acting well. However, these parameters can influence on the filtration process implicitly via direct acting on the respective phase permeability. We also have carried out analysis of the pumping well influence on the filtration process near production well in different practical cases.Key words: computer modeling, oil and gas producing, combined finite element-differences method.Pages of the article in the issue: 114-117Language of the article: Ukrainia

EVALUATION OF OUTER CORE VISCOSITY INFLUENCE ON THE EARTH FORCED NUTATION

On the base of the combined method, consisting of the Sasao, Okubo, Saito (1980) approach with the iteration procedure, allowing couple finite element method with the solution of the Laplace equation, it have evaluated the influence of outer core viscosity on the components of the earth forced nutation. It was derived, that outer core viscosity actually doesn't have influence on the in phase nutation components, but this influence can reach some percents for out of phase nutation components, if we suggest the average value of the outer liquid core viscosity is the order of 1010 Pas

Modeling of the Reservoirs Heating with the Aim of Oil Recovery Increasing

The object of the research is optimal installation of the heat injection wells for reservoirs heating in order to increase oil recovery and, accordingly, support oil production in the hard-reaching heterogeneous reservoirs. One of the most problematic areas in modern oil production is the difficulty of extracting high-viscosity oil from the reservoirs. So far, the most effective method to overcome this problem is the thermal method. However, the possibilities of this method are limited by its high energy consumption and the cost of relevant practice research. Thus, less expensive corresponding methods of mathematical modeling become more important. This investigation uses a combined finite-element-difference method for the non-stationary thermal conductivity problem. Numerical modeling of the temperature distribution around heat injection wells are carried out, taking into account the heterogeneity of the thermal properties of the oil reservoir and the conditions of convective heat exchange at the reservoir's boundaries. The proposed method, due to its high accuracy and convergence of the solutions, allows to obtain reliable practical results and has a number of advantages in comparison with the same research methods. It is established that the process of heating of oil reservoirs is slow and energy consuming, so to increase profitability, it is obviously necessary to use associated production products, such as associated gas. It is shown that less wet layers heat up better and there is no sense to heat the layer for more than two weeks, because the radius of the effective heating area (with a temperature exceeding 80 °C required for outcome of high-viscosity oil from the rock) in this case is sufficient. It is also found that the operation of heat-injection wells is more profitable with their joint interaction, in that case the effective heating area of the oil reservoir and, accordingly, the number of production wells will be the largest. Another hand, the main factor in the location of heat-injection wells is defined by special characteristics of the oil-bearing section of the reservoir in each case. The configurations of the location of heat-injection wells, which were presented in this paper, cover the most optimal cases of the installations of considered oil-bearing section of the reservoirs and can be used in practice