The wells serve as channels connected to the layer to regulate the processes occurring in the hearth. As a result of the well test, monitoring for the indicators obtains information about the process of their exploitation in oil and gas wells and about the sizes of the water-gas and oil layers and near-bottom zones.
Keywords: gas condensate, wells, liquid phase.
Gas and gas condensate under real conditions in the experiment well products always contain small amounts of liquid and so on. The presence of liquid in the gas stream due to moisture, in most cases the combination of heavy components of hydrocarbons in the gas composition, well water pressure, anti-corrosion and anti-hydration depends on the administration of inhibitors. In the well the gas-liquid mixture is complex hydrodynamics process and flow structure diversity and phase change characterized by A change in thermobaric conditions, perforating interval and fountain pipes or international a steady increase in flow rate from bottom to top, removal of condensate and water vapor of liquid phase volume due to condensation flow of reproduction leads to changes in its structure. Pressure for each structure the hydraulics of the particular pipe used in the calculation, it has resistance coefficient, real gas and other parameters.
A well is the essential foundation of a natural gas furnace automation system. If necessary, oil and water are extracted from the well in the form of gas and condensate. The wells serve as channels connected to the layer to regulate the processes occurring in the hearth. As a result of the well test, monitoring for the indicators obtains information about the process of their exploitation in oil and gas wells and about the sizes of the water-gas and oil layers and near-bottom zones.
Exploratory wells are drilled to determine the size and geological structure of the deposits, to study the aquifer systems of the deposit, and to determine the dimensions and productivity of the deposit. Extraction and pressure wells are designed to control the processes that occur in the formation when a natural hydrocarbon source is exploited to extract gas, oil, and condensate. This well complements our guidelines for comprehensive and periodic investigation of the well. The information obtained during the use of this well provides information about the permeability of the reservoir, oil, gas and condensate reserves, and the size of the reservoir.
Monitoring and piezo metric wells are used to investigate the processes occurring in the soil. We can refer to wells drilled in gas or oil fields as sentinel, while piezo metric wells are drilled for the boundary rock (water field) of wells. For such wells, monitoring provides information on the behavior of the furnace, time and volume changes in formation pressure in gas, oil, and water fields, as well as allows the monitor geophysical well to monitor the movement of fluids in gas and oil wells.
First, we will look at the typical moments that accompany the use of a gas well. The first feature is the violation of the straight-line law of percolation, which is conditioned by the high velocities of gas percolation in the bottom burning zone of the layer. An oil well flow rate of 100 m3/cut is considered too high. A flow rate of 1 mln.m3/cut can be assumed for a gas well. Let the layer pressure be 15 MPa and the core pressure be 10 MPa. Then the flow rate of the pressurized gas will be 10,000 m3/cut, and the rate of gas percolation near the bottom of the well is greater than the rate of oil percolation.
As we mentioned before, the effect of the pressure of the layer in the field of several wells is understood as such pressure in the foundation due to its long-term retention. Long-term well retention refers to the time required to equilibrate the well profiles in the considered well area.
The next feature of flow-through collection is the filtration of the gas-condensate mixture (two-phase filtration). When a gas-condensate unit is installed, even with increased formation pressure, the bottom pressure P in each I-u well is less than the pressure P at which condensation started in the well. Condensation in the near-bottom zone and adjacent layer zone changes the percolation resistance A and B in Eq. In the near-bottom zone, two-phase percolation occurs in conflict with the dewatering of well products in boundary or subsurface waters. If the well is not equipped with a special measure to remove the liquid, it can pressurize itself. In the last years of development, the evacuation condition on the flow of liquid fluids into the well is especially deteriorating due to the reduction of gas flows.
Natural gas production is carried out by lowering the formation pressure and core pressure. This causes the layer to change shape. Theoretical and experimental analysis shows the change (decrease) of the permeability and permeability coefficients of the layer according to the decrease of the pressure of the layer. In this case, the transmission coefficients vary more dramatically (up to 90 % and more in the wild). Of course, in addition to the funnel-shaped drop around the well of the liquefied collector, a «permeability funnel» and a «permeability funnel» are formed.
As formation pressure changes, gas properties at core pressure, for example, begin to dictate the predicted flow rate of wells. Estimated calculations show that the error in predicted flow rates for the considered composition of natural gas varies from 10 to 16 % for methane, and from 23 to 28 % for methane, and their correlation with the Boyle-Mariotta law not accounting for real gas variation due to pressure variation.
When the well is drilled, the washing solution filtered in the near-bottom zone of the formation leaks out, and the productive layer becomes clayey. A similar complication of capping an active discharge well prior to overhaul is considered to accelerate flow accumulation. During the zone close to the well, the water is cleaned of dirt and clay cutting, but at some point, the well gas flows and accumulates, and everything is repeated. By allowing the disposal of clay parts, the productivity of the well increases significantly. The different degree of saturation of the product layers, depending on the thickness, determine the different time of adding them to the use of the water balance of the product. These factors should not be overlooked when analyzing a well in a natural gas field feasibility study and analysis project. In just one year, two doctoral dissertations were defended on the problems affecting the near-bottom zone when drilling and overhauling wells, as well as measuring them, and the obstacles to reducing the required well productivity.
Corrosion of the well interior and press equipment may occur simultaneously if the well being used is not properly sized. For a gas well, there is a problem with coning the bottom water. When the oil casing is wetted, the gas and water cones cause complete absorption of the wellbore and decrease the efficiency of the individual well. The efficiency of gas and water flow accumulation in a well depends on the quality of the solids. Depending on the density, the different mechanical properties of the product resin account for the lateral shape near the bottom of the wells. This means that the thickness of the cemented annulus varies with depth. That is, as a result of perforation, different information is obtained from the productive layers and wells. A similar case is considered when the column layout used in the well column is not common. Improper cementing can lead to uncontrolled flow of gas below and above horizons, forming gryphons.
References:
- M. Gafurova, O. Garaeva. Transcripts of general, practical lessons from the course on mastering gas and gas-condensate stoves. Ashgabat, TPI, 2006.
- Shirkovsky A. I. Development and exploitation of gas and gas condensate fields. Textbook. M., Nedra, 1979.
