Review on Relationship Between the Universality Class of the Kardar-Parisi-Zhang Equation and the Ballistic Deposition Model

We have analysed the research findings on the universality class and discussed the connection between the Kardar-Parisi-Zhang (KPZ) universality class and the ballistic deposition model in microscopic rules. In one dimension and 1+1 dimensions deviations are not important in the presence of noise. At the same time, they are very relevant for higher dimensions or deterministic evolution. Mostly, in the analyses a correction scale higher than 1280 has not been studied yet. Therefore, the growth of the interface for finite system size β ≥ 0.30 value predicted by the KPZ universality class is still predominant. Also, values of α ≥ 0.40, β ≥ 0.30, and z ≥ 1.16 obtained from literature are consistent with the expected KPZ values of α = 1/2, β = 1/3, and z = 3/2. A connection between the ballistic deposition and the KPZ equation through the limiting procedure and by applying the perturbation method was also presented.

Novel Mineral Scale Deposition Model Under Different Flow Conditions with or Without Scale Inhibitors

Mineral scale formation causes billions of dollars’ loss every year due to production losses and facility damages in the oil and gas industry. Accurate predictions of when, where, how much, and how fast scale will deposit in the production system and how much scale inhibitor is needed are critical for scale management. Unfortunately, there is not a sophisticated scale deposition model available, potentially due to the challenges below. First, an accurate thermodynamic model is not widely available to predict scale potential at extensive ranges of temperature, pressure, and brine compositions occurring in the oilfield. Second, due to the complex oilfield operation conditions with large variations of water, oil and gas flow rates, tubing size, surface roughness, etc., wide ranges of flow patterns and regimes can occur in the field and need to be covered in the deposition model. Third, how scale inhibitors impact the mineral deposition process is not fully understood. The objective of this study is to overcome these challenges and develop a model to predict mineral deposition at different flow conditions with or without scale inhibitors. Specifically, after decades of efforts, our group has developed one of the most accurate and widely used thermodynamic model, which was adopted in this new deposition model to predict scale potential up to 250 °C, 1,500 bars, and 6 mol/kg H2O ionic strength. In addition, the mass transfer coefficients were simulated from laminar (Re < 2300) to turbulent (Re > 3,100) flow regimes, as well as the transitional flow regimes (2300 < Re < 3,100) which occur occasionally in the oilfield using sophisticated flow dynamics models. More importantly, the new deposition model also incorporates the impacts of scale inhibitors on scale deposition which was tested and quantified with Langmuir-type kink site adsorption isotherm. The minimum inhibitor dosage required can be predicted at required protection time or maximum deposition thickness rate. This model also includes the impacts of entry-region flow regime in laminar flow, surface roughness, and laminar sublayer stability under turbulent flow. The new mineral scale deposition model was validated by our laminar tubing flow deposition experiments for barite and calcite with or without scale inhibitors and laminar-to-turbulent flow experiments in literature. The good match between experimental result and model predictions show the validity of our new model. This new mineral scale deposition model is the first sophisticated model available in the oil and gas industry that can predict mineral scale deposition in the complex oilfield conditions with and without scale inhibitors. This new mineral scale deposition model will be a useful and practical tool for oilfield scale control.

Halite Precipitation in Brine Reservoirs: Prediction and Control by Numerical Model, Optimization of the Fresh Water Treatments and Well Production Regimes

The aim of the work is to optimize the fresh water treatment design, frequency and production regimes (maximize NPV of the well operation) for wells with high NaCl content formation water (brines) production, which are very common for the Eastern Siberia, and forecast productivity index (PI) decline rates and production profiles for the wells by means of halite deposition model for brine flow in porous media united with fresh water treatment model and economic model. New numerical halite deposition model for brine flow in porous media is developed based on Darcy's law and equation of halite precipitation dynamics from formation water taking into account the fresh water treatments, solubility of descipitated halite in the fresh water and permeability profile. It enables to predict deposited halite saturation (Shalite), dynamic porosity and permeability radially and versus time. Thus, we can forecast PI versustime and unite production and economic models,vary fresh water treatment design, frequency andproduction regimes for the given geological conditions and to determine treatment design, frequency and production regimes that brings the maximum NPV.PI decline rates and exploitation factor are calculated and analyzed for different scenarios of the fresh water treatment design, frequency and production regimes. These main conclusions are made from the results of the work:

Assessment of the Impact of Wax Deposition in a Pre-Salt Project

Despite pre-salt fields in Brazil usually having high production per well, one of the areas presents a reservoir with low permoporosity, which results in small flowrates with fluid temperatures during production below the one that is critical for wax deposition. The operations commonly used to remove the wax deposits are diesel soaking and pigging, which brings production losses and OPEX increase. Thus, the economic analysis should consider these events reducing the operational efficiency of production. To evaluate the production drop due to wax deposition, it was necessary to perform a loop test to determine the wax growth throughout time. With a multiphase simulator, it is possible to choose the deposition model and the diffusion coefficient that best fits the analyzed fluid. However, one of the limitations of this first analysis is the lack of data to determine the effect of the shear stripping, as the test is performed under a laminar flow. As this term plays an important role in wax growth, it was necessary to add to the simulation model the shear coefficient fitted from another pre-salt field. With this information, it will be possible to make a more reliable evaluation of the impact of wax deposition, increasing the confidence in the production curve, OPEX and NPV of the full field project. This paper shows the methodology that has been applied to evaluate the impact of wax deposition in pre-salt fields. It presents the deposition model, and its coefficients used to fit the multiphase transient models to a pre-salt field.

The Community Multiscale Air Quality (CMAQ) model versions 5.3 and 5.3.1: system updates and evaluation

The Community Multiscale Air Quality (CMAQ) model version 5.3 (CMAQ53), released to the public in August 2019 and followed by version 5.3.1 (CMAQ531) in December 2019, contains numerous science updates, enhanced functionality, and improved computation efficiency relative to the previous version of the model, 5.2.1 (CMAQ521). Major science advances in the new model include a new aerosol module (AERO7) with significant updates to secondary organic aerosol (SOA) chemistry, updated chlorine chemistry, updated detailed bromine and iodine chemistry, updated simple halogen chemistry, the addition of dimethyl sulfide (DMS) chemistry in the CB6r3 chemical mechanism, updated M3Dry bidirectional deposition model, and the new Surface Tiled Aerosol and Gaseous Exchange (STAGE) bidirectional deposition model. In addition, support for the Weather Research and Forecasting (WRF) model's hybrid vertical coordinate (HVC) was added to CMAQ53 and the Meteorology-Chemistry Interface Processor (MCIP) version 5.0 (MCIP50). Enhanced functionality in CMAQ53 includes the new Detailed Emissions Scaling, Isolation and Diagnostic (DESID) system for scaling incoming emissions to CMAQ and reading multiple gridded input emission files. Evaluation of CMAQ531 was performed by comparing monthly and seasonal mean daily 8 h average (MDA8) O3 and daily PM2.5 values from several CMAQ531 simulations to a similarly configured CMAQ521 simulation encompassing 2016. For MDA8 O3, CMAQ531 has higher O3 in the winter versus CMAQ521, due primarily to reduced dry deposition to snow, which strongly reduces wintertime O3 bias (2–4 ppbv monthly average). MDA8 O3 is lower with CMAQ531 throughout the rest of the year, particularly in spring, due in part to reduced O3 from the lateral boundary conditions (BCs), which generally increases MDA8 O3 bias in spring and fall (∼0.5 µg m−3). For daily 24 h average PM2.5, CMAQ531 has lower concentrations on average in spring and fall, higher concentrations in summer, and similar concentrations in winter to CMAQ521, which slightly increases bias in spring and fall and reduces bias in summer. Comparisons were also performed to isolate updates to several specific aspects of the modeling system, namely the lateral BCs, meteorology model version, and the deposition model used. Transitioning from a hemispheric CMAQ (HCMAQ) version 5.2.1 simulation to a HCMAQ version 5.3 simulation to provide lateral BCs contributes to higher O3 mixing ratios in the regional CMAQ simulation in higher latitudes during winter (due to the decreased O3 dry deposition to snow in CMAQ53) and lower O3 mixing ratios in middle and lower latitudes year-round (due to reduced O3 over the ocean with CMAQ53). Transitioning from WRF version 3.8 to WRF version 4.1.1 with the HVC resulted in consistently higher (1.0–1.5 ppbv) MDA8 O3 mixing ratios and higher PM2.5 concentrations (0.1–0.25 µg m−3) throughout the year. Finally, comparisons of the M3Dry and STAGE deposition models showed that MDA8 O3 is generally higher with M3Dry outside of summer, while PM2.5 is consistently higher with STAGE due to differences in the assumptions of particle deposition velocities to non-vegetated surfaces and land use with short vegetation (e.g., grasslands) between the two models. For ambient NH3, STAGE has slightly higher concentrations and smaller bias in the winter, spring, and fall, while M3Dry has higher concentrations and smaller bias but larger error and lower correlation in the summer.