The sodium 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydropyrimidine-4-olate quantitative content determination in a standard sample

Introduction. The standard samples (SS) use is a necessary condition for the medicines' quality control implementation. Their development is an urgent problem for the pharmaceutical industry, especially for new biologically active compounds that can be further used as pharmaceuticals.Aim. This work aim is to establish the 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydro pyrimidone-4-olate sodium quantitative content, for which anti-inflammatory and analgesic activity was previously proven, in a standard sample.Materials and methods. This work aim is to establish the 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydro pyrimidone-4-olate sodium quantitative content, for which anti-inflammatory and analgesic activity was previously proven, in a standard sample. The main method for establishing a substance quantitative content in the SS is the material balance method. The water determination was carried out according to K. Fisher's method (semimicro method). Sulphated ash was determined according to the XIV edition Russian Federation State Pharmacopoeia General Pharmacopoeia Monograph "Sulphated ash". Related impurities and their content were assessed using the HPLC method on a Flexar liquid chromatograph equipped with a diode array detector (Perkin Elmer, USA). The residual solvents' determination was carried out by the headspace method using a gas chromatograph GC-2010Plus Shimadzu with a flame ionization detector. As an additional method for establishing the main component quantitative content, acidimetric titration with the equivalence point potentiometric indication was carried out.Results and discussion. The percentage was determined for the following indicators: water, residual organic solvents, related impurities, sulphated ash. Using the material balance method, it was found that the 5-butyl-1,2-diphenyl-6-oxo-1,6-dihydropyrimidin-4-olate sodium percentage in a standard sample is 96.01 ± 0.50 %. It was found by acidimetric titration that the 5-butyl-1,2-diphenyl-6-oxo 1,6-dihydropyrimidin- 4-olate sodium quantitative content in SS is 95.12 ± 0.02 %. The difference in the certified value can be explained by the fact that during titration, the SS aciform is released, which precipitates in an aqueous medium and contributes to a shift in the equilibrium and pH value. Consequently, the equivalence point is reached somewhat earlier. However, the data are practically comparable, but it is necessary to use the value obtained by the material balance method.Conclusion. A standard sample certification parameters were determined: water content, residual organic solvents, sulphated ash, related impurities. The main component quantitative content was determined using the material balance method and titrimetry (acidimetry with the equivalence point potentiometric indication).

The Integration of Analytical P/Z Material Balance Method with Static Modeling and Integrated Asset Model IAM to Generate Reliable Forecasting for a Giant Onshore Gas Field in Abu Dhabi

FGIIP (Field Gas Initially in Place) is one of the most essential elements in building dependable static and Integrated Asset Model (IAM). A good estimation of FGIIP will improve history matching and generate reliable forecast. The mature gas field producing under depletion mode is an ideal example where P/Z technique can fit well to re-estimate the FGIIP. Even more, the estimation is also important to narrow down FGIIP uncertainties that initially existed in static model. Reliable FGIIP estimation is achieved by performing multiple P/Z calculations. The process involves dividing reservoir into key areas and each area is represented by individual P/Z prior to summing-up all P/Z to get the total FGIIP. Several scenarios are developed by defining key areas based on permeability variation, areal distribution and PVT behavior. The best FGIIP estimation is then fed back into the static model to generate numerous realizations considering the static uncertainties to produce the same FGIIP. Static models with realistic distribution of properties and good history match are used in the IAM model to generate forecast. The giant onshore gas field is highly heterogeneous having permeability, lateral composition variation and dynamic interaction between wells. To ensure that the heterogeneity observed in the field is honored, multiple key areas are defined by making areal sectorization and lateral PVT variation when estimating FGIIP with P/Z approach. Communication between areas was evidenced from the sectoral P/Z. The field history matching was improved after applying the new estimated FGIIP. It was observed that the sectoral history matching both for production and pressure matches from some selected realizations built in static model resulted in better matches. Succinctly the re-evaluation of static derived FGIIP with P/Z method for the mature gas field was able to reduce the uncertainty range that initially existed. Incorporating the correct estimation of FGIIP in IAM has helped to yield reliable forecast and has enabled the asset to plan proper work programs for further field development. Analytical material balance with P/Z is very applicable for mature gas reservoirs producing under depletion mode. The approach is worth doing to narrow down the uncertainty range that was previously calculated. Moreover, the integration of analytical P/Z with static and dynamic model (IAM) has achieved more reliable forecasting of the mature gas field to proceed with further development plan.

RESERVOIR PERFORMANCE ANALYSIS USING MATERIAL BALANCE METHOD IN GAS FIELD

The RF reservoir is a dry gas reservoir located in Northeast java offshore that has been produced since 2018. The RF reservoir has produced 2 wells with cumulative production until December 2019 is 31.83 BSCF. In January 2018 the gas production rate from the two wells was 36 MMSCFD and the reservoir pressure at the beginning of production was 2449.5 psia, peak production occurred in April 2019 with a gas flow rate of 98 MMSCFD but in December 2019 the gas production rate from both wells decreased to 30 MMSCFD with reservoir pressure decreased to 1607.8 psia. Changes in gas flow rate and pressure in the RF reservoir will affect changes in reservoir performance, so it is necessary to analyze reservoir performance to determine reservoir performance in the future with the material balance method. Based on the results the initial gas in place (IGIP) is 80.08 BSCF. The drive mechanism worked on the RF reservoir until December 2019 was a depletion drive with a recovery factor up to 88% and a current recovery factor (CRF) is 40%. The remaining gas reserves in December 2019 is 39 BSCF and the reservoir will be made a production prediction until December 2032. Based on production predictions of the four scenarios, scenario 2 was chosen as the best scenario to develop the RF reservoir with a cumulative production is 66.1 BSCF and a recovery factor of 82.6%.

wells of gas and gas condensate reservoirs in the South-Eastern part of the Bukhara-Khiva region and methods for increasing their productivity

The article examines the methods of increasing the productivity of wells of gas and gas condensate reservoirs in the south-eastern part of the Bukhara-Khiva region (BHR). The role of gas calculation methods in determining the gas reserve of Mesopotamia in sveza with an increase in the share of gas reserves from 1 to 10 million tons of conventional fuel is shown. Certain difficulties have been identified in the issue of reliable determination of gas reserves in the limited fund of wells and large ranges of changes in calculated parameters. The determining significance of the value of gas reserves in calculating the forecast indicators of the development and technologies of their extraction is justified. It is established that increasing the degree of reliability of calculating gas reserves ensures the efficiency of its extraction, as well as the rational use of material and technical resources and financial capabilities of the enterprise. The advantages of such methods for determining gas reserves as the volume method, the material balance method, and static models are disclosed. A specific description of each of these methods and their application for calculating gas reserves at the Northern Guzar field is given.

Methodology for Constructing Simplified Reservoir Models for Integrated Asset Models

The paper presents the developed methodology for building simplified reservoir models for integrated asset models (IAM) of oil and gas fields: allocation and substantiation of areas, substantiation of model parameters, substantiation of actual weighted average reservoir pressure for areas, history matching and validation, evaluation of effective injection factors, integration in an IAM, prediction calculations, model updating. The novelty of the methodology is the developed approaches and methods of considering different features of fields with a high extent of automation for areas and fields as a whole. Models based on the material balance method and two-dimensional proxy models of one-phase flow in porous media are used as simplified reservoir models in the paper. The developed methodology has been successfully tested for four oil and gas fields of Russia, which have different geological and production features: a large field with a long development history and a large number of active wells, a field with low permeability in all pay zones and high scopes of new wells commissioning, a field with a gas cap and high gas/oil ratios (GOR) for individual wells, a field with a complex system of reservoirs and tectonic faults and a large number of multi-pay production wells. For three out of four fields, at the moment, the IAMs have been transferred to commercial operation based on the pilot projects performed and are used by field specialists to solve the following problems: quality analysis of reservoir pressure measurements; assessments of actual reservoir pressure trends by areas; assessments of ineffective injection for areas; prediction of reservoir pressure, water cut and GOR profiles for wells (up to one year) for various prediction scenarios, including optimization scenarios (taking into account the limitations of the material balance method).

Optimization model of material balance for reservoir energy survey analysis and control

Introduction. When monitoring the development of hydrocarbon fields, the energy state of the reservoirs is monitored. An inaccurate understanding of the current distribution of reservoir pressure leads to the wrong strategy for the development of residual oil reserves. Isobar maps are constructed to assess reservoir pressure for productive formation. The simplest and most common method of map generation (by interpolating the values of the measurements) has a high sensitivity to the coverage of the well stock by well tests and does not take into account the dynamics and compensation of fluid withdrawals. To eliminate these shortcomings, it is proposed to use the method of multi-tank material balance. Objectives. The purpose of the work is to show the possibility of using the multi-tank material balance method (MMB) to reduce the risks related to low current reservoir pressure at the stage of well workover planning under conditions of limitations on the number and duration of well tests and taking into account the history of production / injection, as well as to predict the dynamics of reservoir pressure in the drainage area. Methods. In the MMB model, for each well, its own block (tank) is specified, for which the mathematical balance equation is drawn up, taking into account the crossflow between the blocks. The transmissibility values are obtained iteratively by numerically solving the problem of minimizing the loss function of the discrepancy between the calculated reservoir and bottom hole pressures and their actual values. Results. The paper provides examples of good convergence of the calculated pressures by the MMB method to the actual build-up test results at the wells of the Ural-Volga fields. The possibility of predictive calculations to optimize the reservoir pressure maintenance system is shown. The practical advantages of the method are: relative simplicity of model, automated adjustment of interblock transmissibility. Discussion. The field of application of the MMB method is determined by the tasks in which it is necessary to determine the reservoir pressure in conditions of a lack of fresh measurements. The MMB methodology is applicable to assess reservoir pressure in order to remove risks before well workovers, as well as to predict the optimization of the reservoir pressure maintenance system.

A simple approach to dynamic material balance for a dry-gas reservoir

The dynamic material balance methodology can be used to estimate gas initially-in-place using only production and PVT data. With this methodology, reservoir pressure is obtained without requiring the well to be shut in; it is therefore superior to the static material balance method since there is no loss of production. However, the technique requires iterative calculations and numerical integration of gas pseudotime and is quite complex to implement in practice. A simpler and equally accurate methodology is proposed in this study. It requires only production and PVT data and also does not rely on a shut-in pressure survey. In addition, it requires neither iterative calculations nor numerical integration of gas pseudotime. The results of the analysis include gas initially-in-place and gas productivity index, and can easily be extended to production forecasting. Gas initially-in-place is evaluated with a high degree of reliability. The methodology is successfully tested with two simulated cases and one field case, giving high-accuracy results.

Tight Gas Reservoir Dynamic Reserve Calculation with Modified Flowing Material Balance Method

The determination of dynamic reserves of gas well is an important basis for rational production allocation and development of a single well. The commonly used flow material balance method (FMB method) uses the slope of the curve of wellhead pressure and cumulative production after stable production of gas well to replace the slope of the curve of average formation pressure and cumulative production to calculate the controlled reserves of single well. However, based on the theoretical calculation, the FMB method ignores the change of natural gas compression coefficient, viscosity and deviation coefficient in the production process. After considering these changes, the slope of the curve of the relationship between bottom hole pressure and cumulative production and the slope of the curve of the relationship between average formation pressure and cumulative production are not equal. In order to solve this problem, the influence of pressure on each parameter is considered, and the equation of modified flowing material balance method is derived. The application of Yan'an gas field in Ordos Basin shows that: compared with the results of the material balance method, the result of the flow material balance method is smaller, and the maximum error is 58.816%. The consequence of the modified mobile material balance method is more accurate, and the average error is 2.114%, which has good applicability. This study provides technical support for an accurate evaluation of dynamic reserves of tight gas wells in Yan'an gas field, and has important guiding significance for economic and efficient development of gas reservoir.