Pressure transient analysis provides essential information to evaluate the dimensions of injection induced fractures, permeability damage near the wellbore, and pressure elevation in the injection horizon. For injection wells, shut-in data can be collected and analyzed after each injection cycle to evaluate the well injectivity and predict the well longevity. However, any interactive analysis of the

Punched screen as a stand-alone screen is gaining more and more popularity in Steam Assisted Gravity Drainage (SAGD) operations. However, the literature contains limited studies for proper aperture size selection and the performance of the punched screen. This paper aims at investigating the performance of punched screen and generating an aperture size selection protocol for SAGD production wells.

To attain cement sheath integrity, a tight and ductile microstructure for the cement matrix is desirable. Despite improvements achieved in cement design by employing fiber additives, limitations such as low compressive strength and formation of weak regions may result in fracture initiation points in the cement matrix. In this work we grafted silica nanoparticles on the surface of expandable polymer

Mono ethylene glycol (MEG) has been used as a thermodynamic hydrate inhibitor in the gas industry. Due to its high usage, recoverability and environmental impact, MEG is regenerated instead of releasing to the environment. During the regeneration (distillation) process, MEG is exposed to higher temperatures in the reboiler to remove surplus water. When exposed to high temperatures, MEG thermal degradation

Plugging shale pores and throats with nanoparticles is an efficient and economic method of preventing water invasion to sustain shale wellbore stability. The nanoparticles size distribution is the key factor affecting plugging performance. Currently, the selection of nanoparticle size is usually based on empirical plugging rules and qualitative evaluation experiments. Experimental evaluations only

Robust well placement strategies are decisive for upstream activities in the oil industry. In particular, flow units have been used as an effective model for reservoir characterization and rock typing. However, the interplay between the petrophysical features of flow units, their intrinsic quality, rock mechanics, and ultimate production still deserves investigation. In an earlier paper (Oliveira et al

Tight sandstone gas reservoirs differ greatly in physical properties, and this kind of uncertainties severely set a limit to the steady production and efficient development of gas reservoirs. In order to effectively develop untapped reserves of tight sandstone gas reservoirs and improve their production and recovery, it is important to optimize the well pattern density for the ones with complex reservoir

A robust reservoir surveillance program is key to successful management of a steamflood operation and accurate measurement and proper interpretation of temperature surveys is essential for such a surveillance program. The objective of this study was to look at factors that can impact a temperature log by performing an extensive analysis of field data, primarily gathered from a single company's steamflood

A Mathematical model for total mass flow rate per unit area and total permeability of real gas flow in fractal porous media(FPM)1 was proposed on the basis of fractal theory. Proposed models in this paper paid attention to the influence of real gas effect on gas, taking transition regime as the coupling of slip regime and Knudsen diffusion, considering multi-flow-regime coexist, multi-flow-regime is

Quantitative analysis of mud losses is a direct method for prediction of fracture width, which offers a criterion for designing lost preventive materials and guides early remedial actions. This study presents a mathematical model for prediction of mud loss in naturally fractured formations in two parts. First, a mathematical model is developed considering the fracture deformation and leak-off from

The Permian Jiamuhe Formation in Jinlong-2 Block is an unconventional volcanic reservoir that has been a major target of oil production in the northwest margin of the Junggar Basin, China. This study focuses on analyses of geological, well-logging and production data to understand the characteristics and to set up quantitative evaluation method on volcanic reservoirs. The geological data reveals that

Understanding the status and the relative content of water in shale is of great significance for shale gas and oil reserve estimations and production predictions. In this work, a facile and efficient method to quantitatively determine the status and relative content of water in shale is proposed. As shale composition significantly influences the distribution and status of water, X-ray diffraction (XRD)

The use of residual polymer in the formation after polymer flooding for deep injection-profile control is an important method to further improve oil recovery. In order to evaluate the sensitivity of profile control by clay particles after polymer flooding, 5 influential factors were selected to perform the numerical simulation, including the permeability ratio, formation oil viscosity, injection timing

Dariyan Formation (Aptian) is one of the important hydrocarbon reservoirs in the Persian Gulf. In this reservoir, porosity is controlled by various depositional and diagenetic factors. This study integrates petrographic, geochemical, petrophysical and reservoir quality data to distinguish various pore types and their evolution in two fields selected from the SE and NW Persian Gulf. Primary (depositional)

Alkyl-carboxylate extended surfactants as foaming agents have been formulated to generate stable nanoparticle-surfactant foam systems. Because of their unique characteristics, these extended surfactant contains a carboxylate head group and together with ethylene oxide groups inserted between the alkyl tail and carboxylate head group. They tend to outperform with a low precipitation tendency at high

Comprehensive understandings of the influences of negative pressure on air-leakage and its driving mechanism are critical for controlling methane concentration during coal seam gas extraction. Laboratory experiments were conducted using an integrated apparatus to study the air-leakage process of coal seam gas extraction under different negative pressures. In addition, a coupled computational fluid

In this work we look at MEOR processes including biopolymer production and microbial competition. We have simulated a two-phase system containing of oil, water, nutrients, metabolite (biopolymer) and biofilm using the Matlab Reservoir Simulation Toolbox (MRST) package. Different mechanisms including water viscosity improvement by the action of biopolymer and biofilm formation due to adsorption of bacteria

The accurate information about the magnitude and orientation of in-situ stress in depth contributes to the reasonable design of drilling fluid density and borehole trajectory for avoiding wellbore failure and the associated underground complexity. The technique of estimating the magnitude of the maximum horizontal stress using the wellbore breakout observed from imaging logging has been widely recognized

This study investigated the hydrocracking reaction performance of Mo-dispersed catalysts in relation to operating conditions in a bench scale slurry bubble column reactor. Experiments were performed at various temperatures (405–435 °C), LHSV (0.2–0.45 h−1), superficial gas velocities (0.4–2.2 cm/s) and pressures (80–180 bar). As a result, it was found that the temperature and LHSV influenced the VR

One of the main challenges in oil and gas wells is ensuring wellbore and casing integrity in a CO2 saturated brine environment. The integrity of a well casing relies on its mechanical properties and corrosion resistance to harsh downhole conditions. This paper discloses the results of a mathematical modeling study and experimental investigation conducted to understand the corrosion behavior of carbon

In shale oil reservoirs, cyclic CO2 injection has proven to be effective at recovering significant amounts of oil, however, certain downsides to the use of CO2 exist owing to its corrosive nature and its higher miscibility pressure compared to hydrocarbon gases such as ethane and propane. This paper presents simulation results focused on the impact of phase behavior on the injection of single component

Single-objective well control problems have been studied for many years as one of the most typical optimization problems by researchers worldwide. However, single-objective optimization often could not meet the needs in practical application processes leading to multi-objective optimization problems which have better adaptability in practical applications. In this study, a new method for multi-objective

Impulse oxygen activation logging based on pulsed neutron technique is a widely used method to monitor the injection profile. The instrument utilizes a D-T generator to activate the oxygen nuclei in the borehole and the secondary gamma-rays are measured by the scintillation detector. According to the timing principle, it can detect the water flow and provide a quantitative measure of flow using a serious

Changing the salinity and ionic composition of the injected water and designing “engineered water” (EW) is an enhanced oil recovery approach which affects the wettability of carbonate reservoirs and improves the oil recovery in many cases. Application of nanoparticles also affects oil production by various mechanisms such as altering the wettability, changing the viscosity of the oil and the injected

Hydrate saturation estimation in the field is mainly controlled by proper interpretations of downhole electrical logging data based on Archie's law. However, saturation exponent value in Archie's law is site dependent, and its proper selection for hydrate-bearing sediments is still a challenge. In this study, a fractal model of saturation exponent is derived to show physical connections between saturation

After depletion development stage, the well-utilized approach to enhance recovery of tight oil reservoirs is fluid-injection, involving nitrogen, water, and CO2. Although a great deal of research efforts has been devoted to relevant scope, it is still challenging to identify the appropriate fluid type which can achieve favorable recovery efficiency. Also, the oil-water distribution feature in tight

The quest for effective demulsification materials is growing rapidly in the recent times. Magnetic nanoparticles (MNPs) are an attractive alternative of commercial demulsifiers mainly due to their recyclability and high surface area. Herein, the application of magnetic nanoparticles as demulsifying agents is reviewed. This review covers their synthesis and particularly focusses on how different factors

The radial heterogeneity of near-wellbore formation is frequently encountered in petroleum exploration and production. It usually manifests as the variations of formation wave velocities in radial position. Mapping radial variations of formation velocities is of great significance in identifying invaded zones and determining rock properties, which are valuable for engineering measures, such as fracturing

Bulk property and geochemical analyses were performed on 15 crude oil samples collected from the Early Cretaceous clastic reservoirs in the oilfields of the southern Mesopotamian Basin, South Iraq. Specific gravities ranging between 25.4 and 31.6 API and relatively high sulfur concentrations of up to 1.97 wt % suggest that the samples were generated from kerogen Type II-S at relatively low maturity

This paper developed a new general power-law relation model to predict absolute permeability, which innovatively integrating Poiseuille's law and fractal capillary pressure model. The proposed model took into account the assumption of Poiseuille's law and Purcell theory characterizing the porous media as capillary tubes of various radii. Kewen Li fractal capillary pressure model was preferred to characterize

Lithology is a crucial factor in reservoir characterization. Due to the limited availability of cores, the classes of the subsurface lithologies in boreholes need to be predicted from indirect measurements like well logs. However, the spatial interdependence between sediments and the spatial coupling between the well logs data pose challenges in this lithology classification. Numerous proposed classifiers

Shear velocity log is an important input during the reservoir characterization. It is widely used during seismic reservoir characterization such as lithology, porosity and fluid estimation, four-dimensional seismic studies, geomechanical and wellbore stability studies. Shear velocity log is not necessarily acquired in all wells due to the costs. Therefore, different methods have been developed to estimate

Estimation of rock pore-fluid properties in subsurface reservoirs using seismic reflection data is an important topic in exploration geophysics. Prestack seismic inversion is a key approach for reservoir characterization and fluid discrimination. In this study, we propose a simultaneous estimation approach for discrete fluid facies (i.e., gas, oil, water) and continuous fluid indicators via a Bayesian

Carbon dioxide-enhanced oil recovery (CO2-EOR) technology has been proven to be effective approach for enhancing oil recovery and has been used in conventional reservoirs since 1970s. Tight sandstone reservoir has poor petrophysical properties, and the complex diagenetic processes that make the reservoir highly heterogeneous resulted in posing significant challenges to CO2-EOR technology. This paper

Characterization and detection of natural fractures using well logs in ancient deeply buried dolostones with low matrix porosity are very difficult. Core description, thin section analysis, conventional well logs, borehole image and sonic logs are used to document distribution of fractures in deep Cambrian dolostones in the Tarim Basin, China. The SHmax (maximum horizontal stress) direction is determined

Axial-torsional coupled percussive drilling helps improve the breaking efficiency of hard rock. This paper adopted the simulation method to study the energy transfer efficiency (ETE), and rock damage in axial-torsional coupled percussive drilling with a multiple-button bit. The axial-torsional coupled percussive system model was first built in the finite element calculation platform. And then the

This study investigates the rheology and stability of nanoparticle-stabilized CO2 foams under reservoir conditions (high temperature and high pressure) for fracturing applications. The effects of different parameters on foam apparent viscosity and foam stability were experimentally investigated including the effects of nanoparticle concentration, salinity, foam quality (Γ), shear rate and temperature

A Toe-to-Heel Air Injection (abbreviated as THAI) process is regarded as a promising method in heavy oil and extra heavy oil recovery. Numerical simulations, together with laboratory experiments, were employed to investigate coke zone evolution. The time window of interest focuses on the interval from the commencement of oil production to that of air breakthrough. The simulation results show good history

Modelling of hydraulic fracturing often deals with elastic deformation of rocks and fractures. Some rocks, such as the rock-salt and shale, however, displayed viscoelastic behaviour in both field investigation and lab creep tests. This time-dependent deformation poses a challenge in modelling and characterising of fracture propagation in such formations, thus adding complexity in a multi-physics scenario

Acid-oil emulsion and sludge formation are known as two major formation damage mechanisms and the reason for failure of some acid treatments. The published studies in this area focus primarily on core- to well/reservoir-scale and it is fairly unclear how acid-oil interaction at the pore-scale leads to the formation damage observed at the macro- or core-scale. In this paper, dynamic, micro-scale experiments

Compressed air energy storage (CAES) is a promising energy conversion storage technology and underground salt caverns are recognized as the appropriate storage places for it. The reduction of air during the withdrawal periods leads to the surrounding rock being unloaded, which threatens the stability of the salt cavern. To investigate the mechanical behavior of surrounding rock under different unloading

Porous rocks are the source of important energy resources such as oil and gas that support development worldwide. The quantitative characterization of bound and movable fluid microdistribution is important for reservoir evaluation, productivity prediction, and petroleum recovery. However, due to the complexity of the fluid microdistribution in porous rocks, there is currently no effective method to

First, the extracellular poly γ-(glutamic acid) (PGA) was synthesized by bacillus licheniformis LMG 7559. Then, the applicability of this biopolymer in the microbial enhanced oil recovery (MEOR) was evaluated. The impact of sulfate ions, as strong potential determining ions (PDI's) toward carbonate surfaces, on the stability and performance of PGA flooding, was investigated. The stability of the PGA

The complex formations such as soft-hard interbedded and strong abrasive strata in ultra-deep wells make the PDC bit inefficient in rock-breaking, which greatly increases the development cost of oil and gas reservoirs. There are two basic ways to solve the above problems: one way is to relieve the force condition of the bit by changing the working mode and the other is to release the stress of the

Occurrence state of fluids in the microscale pores of tight reservoirs significantly affects the flow behavior and recoverability of reservoir fluid. Currently, microfluidic technique and CT (Computed Tomography) scanning have been widely applied on the reservoir pore structure evaluation and fluid flow behavior characterization due to their high resolution. In this study, combining a microfluidic

Steam-assisted gravity drainage (SAGD) methods have been widely applied in oil-sands exploitation globally. SAGD processes are effective only after thermal and hydraulic communication between the injector and producer has been established during the start-up operation of the well pair. The geomechanical SAGD dilation startup has been considered a promising technology that can enhance permeabilities

In this study, the deposition rate of asphaltene particles is modeled considering the asphaltene particles interactions using the population balance approach. The modeling consists of three sub-models: (1) The distribution of the asphaltene particles along the pipe, (2) The transfer of asphaltene particles from the bulk to the wall using the Eulerian approach, (3) Adhesion of asphaltene particles to

Studying the fundamental influence of basin-floor topography on the growth and morphology of sedimentary systems has largely focused on submarine fans; however, in lacustrine settings, only a limited number of studies are primarily concerned with confined sublacustrine fans, although such fans can form high-quality hydrocarbon reservoirs. By using recently acquired three-dimensional seismic data, a

The study of pore network evolution is an important aspect of tight shale reservoir characterization. Pore spaces in shales consist of three major types: interparticle pores and intraparticle pores associated with mineral matrix and organic-matter pores. In this study, the evolution of pore networks for each pore type in lacustrine shales during thermal maturation was studied based on a suite of 19