Constraining the Conditions of Scale Deposition in a Gas Condensate Well: A Case Study

2014 ◽  
Author(s):  
R. A. McCartney ◽  
SPE, S. Duppenbecker ◽  
R.. Cone
Keyword(s):  
Produced Water ◽  
Gas Condensate ◽  
Flow Profile ◽  
Formation Water ◽  
Zone Formation ◽  
Water Rates ◽  
Wide Range ◽  
Management Plans ◽  
Water Saturated ◽  
Scale Deposition

Abstract Field X is a gas condensate field where the wells produce primarily gas and a small amount of formation water mixed with condensation water (<19 Sm3/d per well). Unexpectedly, scale (aragonite, possibly with minor sulfate minerals) was identified in Well A during a routine PLT. To aid scale mitigation planning, the cause of scale deposition has been investigated using scale prediction software. A wide variety of data and information has been used to constrain and verify the scale predictions and as a result they are consistent with the observed type, volume and location of scale, PLT results (inflow temperature, hydrocarbon flow profile), produced water and formation water Ca and Cl concentrations, and production data (hydrocarbon and total water rates). A novel method was developed to estimate the composition of formation water entering the well from produced water analyses (mixtures of condensation and formation water) and where produced water rates are available this can also be used to estimate the rate of flow of formation water into the well. The results suggest that formation water enters the well at low rates (∼1m3) from the upper perforated zone (Formation 1) whilst water-saturated hydrocarbons enter from both the upper and lower zones (Formations 1 and 2). The formation water Cl concentration is between ∼5, 100 and ∼11, 000 mg/L and the Ca concentration may be between ∼121 and ∼177 mg/L. Partial evaporation of formation water (due to pressure decline and Joule-Thomson heating) as it enters the well causes scale deposition. The remaining formation water is produced along with water condensing from gas. An additional risk of total salt deposition in these wells was also identified. This study has shown how a wide range of data can be used to constrain the conditions of scale deposition in such wells. The results of this study are being used to develop scale management plans for the field.

Forecasting the Water Flooding for the Production Wells of a Gas Condensate Field with a Fractured Reservoir Type

2021 ◽  
Author(s):  
Pavel Dmitrievich Gladkov ◽  
Anastasiia Vladimirovna Zheltikova
Keyword(s):  
Produced Water ◽  
Fractured Reservoirs ◽  
Gas Condensate ◽  
Water Flooding ◽  
Fractured Reservoir ◽  
Well Performance ◽  
Integrated Monitoring ◽  
Field Development ◽  
Water Gas ◽  
Gas Ratio

Abstract As is known, fractured reservoirs compared to conventional reservoirs have such features as complex pore volume structure, high heterogeneity of the porosity and permeability properties etc. Apart from this, the productivity of a specific well is defined above all by the number of natural fractures penetrated by the wellbore and their properties. Development of fractured reservoirs is associated with a number of issues, one of which is related to uneven and accelerated water flooding due to water breakthrough through fractures to the wellbores, for this reason it becomes difficult to forecast the well performance. Under conditions of lack of information on the reservoir structure and aquifer activity, the 3D digital models of the field generated using the hydrodynamic simulators may feature insufficient predictive capability. However, forecasting of breakthroughs is important in terms of generating reliable HC and water production profiles and decision-making on reservoir management and field facilities for produced water treatment. Identification of possible sources of water flooding and planning of individual parameters of production well operation for the purpose of extending the water-free operation period play significant role in the development of these reservoirs. The purpose of this study is to describe the results of the hydrochemical monitoring to forecast the water flooding of the wells that penetrated a fractured reservoir on the example of a gas condensate field in Bolivia. The study contains data on the field development status and associated difficulties and uncertainties. The initial data were results of monthly analyses of the produced water and the water-gas ratio dynamics that were analyzed and compared to the data on the analogue fields. The data analysis demonstrated that first signs of water flooding for the wells of the field under study may be diagnosed through the monitoring of the produced water mineralization - the water-gas ratio (WGR) increase is preceded by the mineralization increase that may be observed approximately a month earlier. However, the data on the analogue fields shows that this period may be longer – from few months to two years. Thus, the hydrochemical method within integrated monitoring of development of a field with a fractured reservoir could be one of the efficient methods to timely adjust the well operation parameters and may extend the water-free period of its operation.

Petrophysical Type Curves for Identifying the Electrical Character of Petroleum Reservoirs

2007 ◽  
Vol 10 (06) ◽  
pp. 711-729 ◽  
Author(s):  
Paul Francis Worthington
Keyword(s):  
Water Saturation ◽  
Early Stage ◽  
Well Logs ◽  
Log Analysis ◽  
Well Log ◽  
Formation Water ◽  
Water Conductivity ◽  
Core Data ◽  
Water Saturated ◽  
Petrophysical Evaluation

Summary A user-friendly type chart has been constructed as an aid to the evaluation of water saturation from well logs. It provides a basis for the inter-reservoir comparison of electrical character in terms of adherence to, or departures from, Archie conditions in the presence of significant shaliness and/or low formation-water salinity. Therefore, it constitutes an analog facility. The deliverables include reservoir classification to guide well-log analysis, a protocol for optimizing the acquisition of special core data in support of log analysis, and reservoir characterization in terms of an (analog) porosity exponent and saturation exponent. The type chart describes a continuum of electrical behavior for both water and hydrocarbon zones. This is important because some reservoir rocks can conform to Archie conditions in the fully water-saturated state, but show pronounced departures from Archie conditions in the partially water-saturated state. In this respect, the chart is an extension of earlier approaches that were restricted to the water zone. This extension is achieved by adopting a generalized geometric factor—the ratio of water conductivity to formation conductivity—regardless of the degree of hydrocarbon saturation. The type chart relates a normalized form of this geometric factor to formation-water conductivity, a "shale" conductivity term, and (irreducible) water saturation. The chart has been validated using core data from comprehensively studied reservoirs. A workflow details the application of the type chart to core and/or log data. The analog role of the chart is illustrated for reservoir units that show different levels of non-Archie effects. The application of the method should take rock types, scale effects, the degree of core sampling, and net reservoir criteria into account. The principal benefit is a reduced uncertainty in the choice of a procedure for the petrophysical evaluation of water saturation, especially at an early stage in the appraisal/development process, when adequate characterizing data may not be available. Introduction One of the ever-present problems in petrophysics is how to carry out a meaningful evaluation of well logs in situations where characterizing information from quality-assured core analysis is either unavailable or is insufficient to satisfactorily support the log interpretation. This problem is especially pertinent at an early stage in the life of a field, when reservoir data are relatively sparse. Data shortfalls could be mitigated if there was a means of identifying petrophysical analogs of reservoir character, so that the broader experience of the hydrocarbon industry could be utilized in constructing reservoir models and thence be brought to bear on current appraisal and development decisions. Here, a principal requirement calls for type charts of petrophysical character, on which data from different reservoirs can be plotted and compared, as a basis for aligning approaches to future data acquisition and interpretation. This need manifests itself strongly in the petrophysical evaluation of water saturation, a process that traditionally uses the electrical properties of a reservoir rock to deliver key building blocks for an integrated reservoir model. The solution to this problem calls for an analog facility through which the electrical character of a subject reservoir can be compared with others that have been more comprehensively studied. In this way, the degree of confidence in log-derived water saturation might be reinforced. At the limit, the log analyst needs a reference basis for recourse to capillary pressure data in cases where the well-log evaluation of water saturation turns out to be prohibitively uncertain.

Gettering Processes for Sub-Micron VLSI

1986 ◽  
Vol 76 ◽  
Author(s):  
John Andrews
Keyword(s):  
Defect Density ◽  
Back Surface ◽  
Dislocation Network ◽  
Published Data ◽  
Interstitial Oxygen ◽  
Supersaturation Ratio ◽  
Zone Formation ◽  
Wide Range ◽  
Dry Oxidation ◽  
P Diffusion

ABSTRACTGettering by the dislocation network caused by P-diffusion into the back surface of Si wafers at 950° C for 1 hr. is often used for VLSI. However, transistors with sub-micron gates are jeopardized at 950°C because of possible source-drain punch through by lateral P-diffusion. The temperature dependence of gettering by P-diffusion has been investigated at 950, 900, and 850°C. Gettering by P-diffusion was found to be marginal at 900°C and totally ineffective at 850°C.Recently published data on the solubility and diffusivity of interstitial oxygen in Czochralski-grown Si has been used to develop a simple out-diffusion model for denuded zone formation during thermal oxidation. Comparison with experimental observations on samples with high interstitial SiO2 concentration [Oi]0, exposed to dry oxidation at 1100° C for various times up to 8 hrs. and followed by 24 hr. anneals in N2 at 700°C and 1050°C, reveal that SiO2 precipitation occurs when the supersaturation ratio exceeds 4.7. The model implies an optimum denuding temperature near 100° C for a dry oxidation time of 4 hrs. The bulk defect density was also observed to decrease more than a factor of 5 as the denuding time was increased from 0 to 8 hrs.Intrinsic gettering by SiO2 precipitates in Czochralski-grown silicon has been evaluated over a wide range of initial interstitial oxygen concentrations 15 < [Oi]0 < 22 ppma with and without a HI-LO-HI pre-process annealing cycle. Among samples of approximately 100 p-n junctions per wafer, reductions of 1–3 orders of magnitude in reverse leakage at 5 volts were achieved in the worst 10% of 500 μm square devices on wafers that were exposed to the HI-LO-HI heat treatment. Intrinsic gettering is most effective when [Oi]0 22 ppma, but leakage reduction among the worst diodes is achieved at the expense of a 2 or 3-fold increase in median leakage.

Iterative modeling is as a tool for selecting a geological basis for hydrodynamic modeling and development design

2021 ◽  
pp. 111-126
Author(s):  
A. A. Agarkova ◽  
S. E. Shebankin ◽  
M. A. Tukaev ◽  
M. S. Karmazin
Keyword(s):  
Initial Data ◽  
Hydrodynamic Modeling ◽  
Usual Method ◽  
Gas Condensate ◽  
Digital Model ◽  
Geological Model ◽  
Field Case ◽  
Field Development ◽  
Wide Range

The usual method for constructing a digital model of a field is based on hydrodynamic modeling using the basic implementation of a geological model, usually requires additional adjustments to the initial data, and as a result, leads to a wide range of uncertainties in assessing the predicted technological indicators of field development. The PK1 reservoir of a gas condensate field case study discuss-es the method of iterative modeling, which makes it possible to comprehensively approach the assessment of possible uncertainties.

Applied Novel Quality Check Method for PVT Data with High Impurities Using Various Samples from Malaysian Fields

2021 ◽  
Author(s):  
Luky Hendraningrat ◽  
Intan Khalida Salleh
Keyword(s):  
Molecular Weight ◽  
Equation Of State ◽  
Gas Phase ◽  
Oil And Gas ◽  
Comprehensive Evaluation ◽  
Gas Condensate ◽  
Fluid Composition ◽  
Essential Information ◽  
Pvt Data ◽  
Wide Range

Abstract PVT analysis of reservoir fluid samples provides essential information for determining hydrocarbon in place, depletion strategy, and hydrocarbon flowability. Hence, quality checking (QC) is necessary to ensure the best representative sample for further analysis. Recently, a novel tool based on Equation of State (EOS) was introduced to tackle the limitation of the Hoffmann method for surface samples with high impurities and heavier components. This paper presents comprehensively evaluating a novel EOS-based method using various PVT data from Malaysian fields. Numerous PVT separator samples from 30 fields with various reservoir fluids (Black Oil, Volatile, and Gas Condensate) were carried out and evaluated. The impurities contain a wide range of up to 60%. The 2-phase P-T (pressure and temperature) diagram of each oil and gas phase before recombination was calculated using PVT software based on Equation of State (EOS). The 2-phase P-T diagram was created and observed the intersection point as calculated equilibrium at separator conditions. Once it is observed and compared with written separator condition in the laboratory report and observed its deviation. Eventually, the result will be compared with the Hoffmann method. The Hoffmann method is well-known as a traditional QC method that was initially developed using gas condensate PVT data to identify possible errors in measured separator samples. If the sample has high impurities and/or heavier components, the Hoffmann method will only show a straight line to the lighter components and those impurities and heavier components will be an outlier that engineers will misinterpret that it has errors and cannot be used for further analysis such PVT characterization. The QC using EOS-based were conducted using actual fields data. It shows potential as novel QC tools but observed only less than 10% of data with complete information that can meet intersection points located precisely similar with reported in the laboratory. There is some investigation and evaluation of the EOS-based QC method. First, most of the molecular weight of the heavier fluid composition of gas and oil phase was not reported or used assumptions especially when its mole fraction is not zero. Second, properties of heavier components of the oil phase (molecular weight and specific gravity) were not measured and assumed similar as wellstream. Third, pressure and temperature data are inconsistent between the oil and gas phase at the separator condition. This study can provide improvement in laboratory measurement quality and help engineers to have a better understanding of PVT Report, essential data requirements, and assumptions used in the laboratory. Nevertheless, the Hoffmann method can be used as an inexpensive QC tool because it can be generated in a spreadsheet without a PVT software license. Both combination techniques can provide a comprehensive evaluation for separator samples with high impurities before identifying representative fluid for further analysis.

Computation of linear elastic properties from microtomographic images: Methodology and agreement between theory and experiment

Geophysics ◽  
2002 ◽  
Vol 67 (5) ◽  
pp. 1396-1405 ◽  
Author(s):  
Christoph H. Arns ◽  
Mark A. Knackstedt ◽  
W. Val Pinczewski ◽  
Edward J. Garboczi
Keyword(s):  
Elastic Properties ◽  
Excellent Agreement ◽  
Fontainebleau Sandstone ◽  
Linear Elastic ◽  
Numerical Predictions ◽  
Wide Range ◽  
Digitized Images ◽  
Water Saturated ◽  
Dry Water ◽  
Theory And Experiment

Elastic property‐porosity relationships are derived directly from microtomographic images. This is illustrated for a suite of four samples of Fontainebleau sandstone with porosities ranging from 7.5% to 22%. A finite‐element method is used to derive the elastic properties of digitized images. By estimating and minimizing several sources of numerical error, very accurate predictions of properties are derived in excellent agreement with experimental measurements over a wide range of the porosity. We consider the elastic properties of the digitized images under dry, water‐saturated, and oil‐saturated conditions. The observed change in the elastic properties due to fluid substitution is in excellent agreement with the exact Gassmann's equations. This shows both the accuracy and the feasibility of combining microtomographic images with elastic calculations to accurately predict petrophysical properties of individual rock morphologies. We compare the numerical predictions to various empirical, effective medium and rigorous approximations used to relate the elastic properties of rocks to porosity under different saturation conditions.

Database for monitoring the spatial management plans of the Polish marine areas. Updating and practical use of data

2018 ◽  
Vol 33 (1) ◽  
pp. 130-138
Author(s):  
Łukasz Szydłowski
Keyword(s):  
Spatial Data ◽  
Database Management ◽  
Planning Process ◽  
Spatial Information ◽  
Local Approach ◽  
Effective Work ◽  
Spatial Management ◽  
Wide Range ◽  
Management Plans ◽  
Marine Areas

Planning and marine spatial development are based on an exceptionally wide range of knowledge and information which are used in the process of creating plans and their later evaluation. The first type is spatial data describing the present state of the natural and anthropogenic environment within a widely understood spectrum. Second type data are statistical information describing spatial occurrence in the environment. Geoinformation within a planning process is hugely important, as the quality of spatial data influences decisions made and final results of planning work. Undoubtedly, efficient spatial database management and creating a compatible system to operate it are the key elements of effective work in a planning process. In Europe, the monitoring process together with creation of tools supporting database management is highly developed. There is a range of examples for the use of the spatial information systems in work linked to preparation and evaluation of spatial management plans at sea. Due to the specifics of works related to spatial planning in Poland, this paper presents a new solution for the future monitoring of the generated plans. The nature of this paper is determined by the local approach to taking advantage of the ArcGis software related with the use of a range of tools in the monitoring approach to plans of spatial management of the Polish marine areas. The purpose is to demonstrate a selected tool which is supposed to improve the planners’ work, from the point of view of the use of statistical data linked to the dynamics of changes in the coastal area. This is an exemplary use of the tool which might be modified at will, according to the needs of a user. Due to such a solution, the tool can be adjusted to the most of required data based on statistical tables.

Sign in / Sign up

Export Citation Format

Share Document