## Blog Archives

## Applied Research

## METHOD FOR INCREASING SPEED AND REDUCING THE ERROR OF MULTIDIMENSIONAL PRECISE LOGIC CONTROLLER

A novel technique has been suggested for increasing multidimensional precise logic controller (MPLC) speed of action based on arrangement of production rules in situation subprograms, initial points of which are registered in special register by fuzzification procedure according to equality to the logical unit of the control parameters precise terms. It enabled to process but one subprogram selected during fuzzification rather than the entire system of the controller production rules without damaging control adequacy in each scanning cycle.

According to their logical nature, each situation subprogram is a software implementation of a production rule, which must be executed when one of the precise terms of each MPLC controlled parameter is equal to a logical unit. The correct assignment of MPLC controlled output variables ranges the microprocessor executes one rule for each multidimensional precise logic controller loop. And to find this rule, the standard procedure for applying to the subprogram is used, which is now well minimized by microprocessor time and storage. It should be noted that in the standard multivariate fuzzy logic controllers the entire system is executed, comprising out of tens or even hundreds of production rules in similar situations in each loop, which leads to a significant decrease in performance.

Two fundamental properties (at any given instant both only one term and only an antecedent of one rule is equal to a logical unit) of precise terms set and production rules systems under consideration are the theoretical basis for improving MPLC speed and reducing its error.

## ANALYTICAL MODEL OF TEMPERATURE AFTER FLOW RATECHANGE

At present time the interest to the quantitative interpretation of temperature surveys is growing. Individual flow rate and reservoir pressure of each layer, behind-casing flow rate, hydrodynamic layer parameters, characterization of permeability changing at near-wellbore zone become the purposes of quantitative interpretation. Non-stationary temperature and pressure in the well are used as input data for transient processes analysis, and temperature logs are used for quasi-stationary analysis. Particular interest is in determination of the individual layer flow rates and near-wellbore zone parameters.

The paper studies the problem of unsteady temperature field in heterogeneous reservoir during fluid filtration. The aim of this work was to develop and provide rationale for simplified analytical model of non-isothermal single-phase fluid filtration in heterogeneous reservoir. Analytical solution for the temperature field in the formation after flow rate changeis obtained by the method of characteristics. Two assumptions were made in solving the problem: radial thermal conduction and compressibility of saturated porous medium are ignored. Analytical models are compared with the numerical solution of the problem. Radial heat conduction and compressibility of oil- or water-saturated reservoirs influence insignificantly on the unsteady temperature field after the flow rate changes.

It is possible to solve the inverse problem on the evaluation of the damage zone radius of the permeability in the reservoir basing on the model curves of the temperature change after flow rate change. The possibility of that method realization is demonstrated on model curves of the temperature change.

## THE INFLUENCE OF DIFFERENT FACTORS ON THE FLAME TEMPERATURE OF THE FLARE UNIT

The article considers the problem of estimation of flame temperature and the study on it the main parameters of a flare. In the typical company in accordance with the terms of reference were designed flare unit designed for burning waste gas in one of the fields of the Russian Federation.

Evaluation of the temperature in the flame front of gas were discharged from the following considerations.

From theory it is known that during the combustion of unmixed gases the flame front is established in those locations where suitable in the combustion zone the flow of reagents (discharged gas and air) are in stoichiometric ratio. The temperature in the flame front is maximized. In this model the combustion process, the temperature of the flame front can be determined from the heat balance equation. The temperature of the flame front , which is an argument in all the components of the right side of the equation, you can determine in deciding this non-linear relative to the temperature equation one way or another. In this paper, for finding temperature was used numerical method for solving nonlinear equations by the method of half division (dichotomy). The paper presents original data and a sample calculation of the temperature-designed flare. The calculation of the effect on the flame temperature of the flare unit of the following factors: flow rate of discharged gas, the diameter of the tip the flare, temperature of discharged gas, combustion efficiency, net calorific value of natural gases and the excess air ratio. The results of this work are engineering methods and a computer program for calculating the temperature used in the analysis of variants of the designed construction of a flare.

## ADAPTATION ACOUSTIC SENSORS, WARNING DEVICES OF SAND AND CONDENSED MOISTURE DSP-EAC-2 IN THE TECHNOLOGICAL LINE GAS COLLECTION POINTUNDERGROUND GAS STORAGE

Carried out fishing activities on adaptation-alarm sensor (DS) and the removal of layers of sand condensed moisture DSP-EAC-2 on the technological line of gas gathering points (GSP) Stavropol underground gas storage (UGS) and Kasimov U Kasimov industrial site of the Office of underground gas storage (UPHG). An essential dependence of sensitivity DS on the installation location, configuration and design features of the operating equipment. The article focuses on the basic principles of calibration modification DS DSP-EAC-2 levels of controlled phases (liquid and solid mechanical impurities) separation methods on the metering Threads GSP, as well as in the process of gas-dynamic studies of wells. Experimental data of the 1st stage adaptation of the sensor DSP-EAC-2 at 108-114 mm diameter pipes. Calibrations The results agree well with the data of the monitoring wells modes. The optimum installation location DSP-EAC-2 based on DC operating conditions. Recommended values are controlled by seven exceedances of water factor for Stavropol UGS and Uvyazov UPHG. It has been shown that it is not advisable to use DSP-2 EAC to monitor the content of sand and water (ERW) on the metering Threads GSP wells in the vicinity of the flow regulating type valves regulating gas control devices (KRU) of the high level of background noise signal. Calibration of acoustic sensors in the gas stream is a prerequisite for obtaining reliable evidence, because it allows to take into account the actual loss of the acoustic signal in the actual configuration of the pipe at the sensor. Uses for normalizing the sensor readings on the level of the acoustic signal by debit gas flow without mechanical impurities is impractical because of the large background used on the thread orifice flow equipment (switchgear). We propose a specific terminology to be used in further work.

## EVALUATION OF FLOW REGIME MULTIPHASE SYSTEMS FOR NUMERICAL HYDRODYNAMIC MODELS

With the development of computer technology in the oil and gas industry, widespread tasks on hydraulic calculation of the modes of transport systems. Analytical solutions based on the use of correlations (Erkezeskor, Beggs and Brill, Grea etc.) in multiphase did not provide a precise definition of the technological parameters of work of system of transportation of oil, gas and condensate. The fundamental error in the application of these methods accumulates due to the incorrect determination of the flow regime.

Currently existing software packages that allow for dynamic calculations (the software package OLGA) require the involvement of highly qualified specialists and a considerable amount of computer time to implement one of the scenario calculations.

In connection with the above issues the question has arisen an urgent task for improving the methods of accounting for the flow regime to calculate the interfacial friction by implementing criteria that determine the flow regime of the multiphase system in the continuous formulation, and compute their correlation with hydrodynamic action. Due to the extreme importance of setting the numerical models for experimental studies are special features that can be later as “speculative” and tabulated the results of experiments. In this work, we will describe the theoretical background for an unambiguous definition of the flow regime.

To determine the flow regime are the following criteria:

– factor of disintegration of components;

– form factor component elements;

– factor degree of fragmentation of the flow components and the perfect forms of the elements.

The result presented work shows the theoretical basis and the algorithm for determining the flow regime of the multiphase system. The application of this methodology makes it possible to perform dynamic calculations, programming, design modules, multiphase flow meters, the construction of nomograms that take into account the flow regime in analytic calculations.