Digital Commons Network^™

Experimental Evaluations Of Selected Sealants To Remediate Co₂ Leakage, Aaron Jeffrey Blue

Masters Theses

"Carbon Dioxide (CO₂) sequestration into porous and permeable brine-filled aquifers is seen as one of the most feasible solutions for reducing the amount of greenhouse gases released into the atmosphere from coal-fired power plants. To safely store the CO₂, it must be trapped under an impermeable rock acting as a seal. One of the concerns with CO₂ sequestration is the generation of new fractures or reopening of existing fractures caused by CO₂ injection in the sealing formation. This project evaluates the potential of sealing these fractures by injecting sealing materials into them. These sealing …

Data Analysis Of Surfactant-Induced Wettability Alteration In Carbonate Reservoirs, Hao Sun

Masters Theses

"Most carbonate formations prove to be oil-wet due to oil aging effect. Therefore it is essential to employ wettability alteration methods for a more effective enhanced oil recovery process. It is confirmed by researchers that surfactant treatment has positive effects on wettability alteration of carbonate rock, from strong oil-wet to intermediate wet or to even weak water-wet. A number of experiments have the same conclusion and yet, a systematic screening guide development with the support of sufficient data analysis is lacking.

This study involves screening guide development for surfactant-induced wettability alteration method. 199 experiments collected from published literatures are analyzed …

Variable Stress Orientations In The Offshore Nile Delta: The Role Of Salt As A Mechanical Detachment Horizon, Weicheng Zhang

Masters Theses

"The offshore Nile Delta is characterized by variations of the maximum horizontal stress orientation in subsalt and supra-salt sequences. Margin-parallel SH, typical for tertiary deltas, is observed for regions that are below or do not contain evaporites. In sequences underlain by evaporates pre-dominantly margin-normal SH is observed. This observation yielded the first conclusive in situ evidence that salt acts as a mechanical detachment layer. In this study, 3D finite element analysis (FEA) is used to simulate the total stress distribution in the offshore Nile Delta featuring evaporate sequences. Several parameters such as different salt sequence geometries, friction coefficient on faults, …

Study On The Applicability Of Relative Permeability Modifiers For Water Shutoff Using Numerical Simulation, Dheiaa Khafief Khashan Alfarge

Masters Theses

"Water production is a challenging problem to be controlled during hydrocarbon-reservoirs production life. Disproportionate Permeability Reduction (DPR) is often used as water shutoff treatment in production wells when other conventional solutions like mechanical isolations are difficult to perform. This study applied numerical simulation methods to diagnose the factors impacting DPR treatment success on macroscopic level and to see when, where and at which conditions DPR treatment can give best results.

This work indicated that the following points should be considered before DPR treatment is executed in any reservoir to get a successful treatment. Firstly, this research explored that DPR performance …

Shale Instability Of Deviated Wellbores In Southern Iraqi Fields, Ahmed Ali Shanshool Alsubaih

Masters Theses

"Wellbore instability problems are the cause for the majority of nonproductive time in the southern Iraqi fields' developments. The most severe problem in terms of effort and disbursement which is referred to a pipe sticking in Tanuma shale formation. Examining the drilling data revealed that this phenomenon was mostly related to the shear failure of the wellbore. Thus, a geomechanical analysis and drilling parameters/ practice optimization analysis were performed on a field in southern Iraq based on data from 45 deviated wells. The geomechanics analysis predicted the suitable drilling fluid density to prevent onset shear failure by using the Mogi-Coulomb …

Mechanistic Understanding Of Water-Rock Interactions During High-Salinity Water-Flooding Of Carbonate Reservoirs, Pu Han

Masters Theses

"Chemically tuned water-flooding provides a relatively cheap method of enhanced oil recovery from carbonate and sandstone reservoirs. Several possible recovery mechanisms such as mineral dissolution, multi-component ion exchange, double-layer expansion, adsorption/desorption from rock surface, reduction in interfacial tension, and fines migration that have been proposed are widely debated. The combination of these processes may result in wettability alteration that increases sweep efficiency of water-flooding. Here, wettability alteration due to water-rock interactions will be examined numerically.

To evaluate the wettability alteration, separation between breakthrough curves of the non-reactive component and the cations based on the chromatographic separation will be used due …

Evaluating Completion Performance For Gas Wells In The Upper And The Lower Montney Formation, Canada, Omar Qasim Mohammed

Masters Theses

"Identifying the key drivers for success of multiple fractured horizontal wells is not straightforward, especially in unconventional reservoirs like the Montney. Al-Alwani et al. (2015) provided a statistical analysis of Montney completions based on publicly available data. They showed that for the entire well population, cumulative gas recovery per stage, declines as the number of completed stages increase. However, their statistical analysis did not differentiate between completions in the Upper/Middle/Lower Montney, and did not include perforation cluster data.

This work documents the statistical analysis of 296 cased-hole horizontal gas well completions reported in the Upper and the Lower Montney. The …

Characterization Of Fracture Initiation In Non-Cylindrical Buckle Folds Using 3d Finite Element Analysis, Eli Jacob Steinbeck

Masters Theses

"The spatial distribution of fracture sets associated with buckle folds has been well documented in field studies. There are difficulties, however, in placing accurate constraints on the timing of the initiation of individual fracture sets during the deformation history of the fold under in-situ conditions. This study investigates specific conditions that give rise to the initiation of various fracture sets in the hinge and limb of a pericline, based on an analysis of the effective stress evolution during the processes of buckling and erosional unloading. A 3D finite element modeling approach is used to simulate the effective stress evolution in …

Mitigation Of Wellbore Instability In Deviated Wells By Using Geomechanical Models And Mpd Technique, Husam Raad Abbood

Masters Theses

"During drilling operations for the E oilfield in the Mishrif formation in southern Iraq, stuck pipe presents a significant wellbore stability problem for deviated wells. In this study, two solutions are utilized to address this problem. The first approach is a 1-D Geomechanical model of the Mishrif formation compiled based on the state of stress and rock strength parameters. It is utilized to assess the contribution of borehole collapse leading to the stuck pipe problems. The results of this study show that wells characterized by stuck pipe are drilled along azimuths which promote wellbore collapse. Three different failure criteria, the …

Exploring Reservoir Connectivity With Production Data: Two New Methods And A New Technique, Ghazwan Faisal Jasim Al-Khmaysawee

Masters Theses

"This study presents two new, simple methods to explore reservoir connectivity, which has a significant impact on field development strategy. Identifying reservoir connectivity during primary depletion plays an important role in achieving the most cost-effective and highest production possible. It is also very important in future secondary and tertiary oil recovery, particularly when costs dictate a limited number of wells such as those in deepwater environments.

The presented methods are reciprocal-productivity index versus total field material-balance time trend lines and reciprocal-productivity index versus time trend lines. Those two methods are quick, simple, inexpensive, and only need rate and pressure data …

An Investigation Of Plugging And Increasing Oil Recovery In Sandstone Porous Media By Micrometer-Size Particle Gel, Haifeng Ding

Masters Theses

"Micrometer-size particle gel (microgel) has been developed and successfully applied to improve conformance in mature reservoirs. However, quite few researches have been published to address on their effect on oil recovery and rock permeability modification.

This work conducted a series of core flooding experiments to investigate the injectivity, plugging efficiency and improving oil recovery potentials of a couple of microgels synthesized in our lab.

First, this work studied the impact of permeability and crosslinker concentration on PAM type microgel treatment. Results shows that microgel treatment would have a less plugging efficiency in lower permeability rocks, which could be caused by …

Impact Of Repeated Cyclic Production Scheme On Eur In Low-Permeability Reservoirs, Samarth Gupte

Masters Theses

"Productivity in low-permeability reservoirs declines quickly compared to conventional reservoirs. These tight reservoirs have very high initial oil production rates but as soon as the oil near the fractured area is recovered, the production declines rapidly making economic oil and gas production a challenge for the industry. This study investigates the impact of repeated shut-in/production cycles on the ultimate recovery of oil in such environments.

A reservoir model with multiple fractured horizontal well having 30 transverse fractures is created using CMG. Reservoir permeability is varied over the range of 0.000001 md to 10 md and shut-in/production cycles of 2-weeks, 1-month, …

Computational Fluid Dynamic Analysis In High Permeability Hydraulic Fractured Horizontal Gas Wells, Hrithu Vasudevan

Masters Theses

"Hydraulic fracturing of horizontal wells in unconventional reservoirs has become the dominant type of well completion performed in the United States. In very low permeability reservoirs (~.00001-.0001 mD), the wellbore is aligned with the minimum horizontal stress, and the completion includes multiple transverse fractures. These fractures may be placed with either open hole sleeve type completion systems (OHMS), or cased hole plug and perf systems (P-n-P). In slightly higher permeability reservoirs (1 to 10 mD) multiple longitudinal fractures have been found to be preferred to completions with transverse fractures.

This study presents an evaluation of gas well productivity for both …

A Comprehensive Study Of Lost Circulation With Application In The South Rumaila Field, Iraq, Abo Taleb Tuama Al-Hameedi

Masters Theses

“Drilling mud losses and problems associated with lost circulation while drilling account for a major expense in drilling oil and gas wells. By industry estimates, more than 2 billion USD is spent annually to combat and mitigate this problem (Ali et al., 2015).

The South Rumaila field in Iraq is one of the largest oilfields in the world. Wells drilled in this field are highly susceptible to lost circulation problems when drilling through the Dammam, Hartha and Shuaiba formations. Lost circulation events range from seepage losses to complete loss of the borehole and are a critical issue in field development. …

Evaluation Of Highly Viscous Polymeric Fluids And Recrosslinked Degraded Gel, Danlu Zhang

Masters Theses

”This work presents the evaluations of two products. One can be used for hydraulic fracturing to achieve viscosity stable under high shear rate, and the other is potential to be applied to enhance oil recovery from mature oilfield.

The first experiment is to synthesize and evaluate a new polymeric fracturing fluid that can resist high shear rate of 511^-1 with favorable viscosity. Zirconium crosslinked fracturing fluids are lack of self-healing ability after shearing, and the difficulties still exist in maintaining viscous with lower polymer content exposed to high shearing conditions, therefore, the research is trying to develop a new …

Fluid Flow Through Deformation Band, Huining Zhang

Masters Theses

"Cataclastic deformation bands, which are common in porous sandstone, have the potential to restrict fluid flow. Geological studies have shown that permeability of deformation band shear zones can be one to five orders of magnitude less than for the sandstone host rock. However, recent studies based on simplified analytical estimates have shown that fluid flow in jointed deformation bands may not be retarded since joints play an important role in conducting fluids. In this study, 2 dimensional finite element analysis (FEA) is used to simulate the total discharge flow rate through jointed deformations. Variations of single planar and conjugate jointed …

Conceptual Parameters Necessary For Modeling Wettability Alteration In An Enhanced Smart Brine-Chalk System, Ahmed Abdulkareem Hussein Albahrani

Masters Theses

"Achieving higher recovery of oil from proven carbonate reserves around the world is not an easy task. One promising new method, especially for carbonate reservoirs, is the use of "Smart Water" technology, which is an injection water with carefully determined, optimal ionic composition and salinity. Recent experiments have shown good recovery results, but the mechanism of wettability alteration by this fluid are still not well understood. The goal of this study is to review the high and optimal salinity and ionic composition literature plus perform dimensional analysis of key variables in order to shed light on the physical and chemical …

Sensitivity Analysis Of Geomechanical Parameters In A Two-Way Coupling Reservoir Simulation, Hector Gabriel Donoso

Masters Theses

"Currently reservoir simulators model geomechanical effects such as compaction, subsidence, fault reactivation, breach of the seal integrity, etc. using only the rock compressibility to change the pore volume. However, rock compressibility as a scalar quantity is unfit to represent the true rock mechanics in the reservoir. In order to accurately represent geomechanical effects in a reservoir simulation, a two-way coupling simulation of the stress analyzer and the reservoir simulator was done. Based on the poroelasticity theory during the production or depletion of the reservoir the porosity and permeability changed due to the stress or pore pressure changes.

A sensitivity analysis …

Single Phase Gas Flow Response Of Fractured Horizontal And Vertical Wells To Repeated Production, Divya Kandlakunta

Masters Theses

"Historically, the conventional approach to well production has been to produce continuously, minimizing interruptions to flow insofar as possible. Yet some operators have observed improved well flow rates and ultimate recovery after a significant well shut-in periods. These production increases have not been documented. This study investigates the production impact of cyclic production/shut-in on fractured vertical and horizontal gas well performance.

A numerical reservoir model in Stimplan software was used to model production in fracture stimulated vertical and horizontal gas wells. Reservoir permeability is varied over a range of 0.0001 md to 1 md, and the shut-in period was varied …

Study And Development Of Robust Preformed Particle Gels For Conformance Control, Yifu Long

Masters Theses

"To improve the oil recovery of mature reservoirs, technologies referring to conformance control have been widely developed and implemented. Among various technologies, preformed particle gel (PPG) treatment has attracted increasing attentions. PPGs, as a kind of deformable plyometric superabsorbent, could be pumped through injection wells as plugging agents to block the fracture or high-permeability zone in a reservoir.

In decade usage of PPGs, an intensively employed material is poly(acrylamide) (PAM) based hydrogel. However, conventional PAM gel did reveal deficient in formidable conditions, such as formations with high temperature and high salinity. Therefore, a novel PPG based on starch-grafting-poly(acrylamide)/nano-composite (SAC) hydrogel …

Correlation Anaylsis Of Magnesite Dissolution Rate And Magnesite Spatial Distribution, Yao Wang

Masters Theses

"This thesis presents a correlation analysis of the spatial distribution and permeability of magnesite dissolution and focuses on its overall rate and average porosity. Magnesite dissolution is affected by several aspects.

A reservoir's large spatial distribution can make capturing the magnesite dissolution difficult, so in this study, a variogram was built in Petrel using a percentage variation of magnesite and sand. The variogram also handles different major and minor directions in anisotropy. After building the magnesite model, simulation of magnesite dissolution was achieved in Cruch Flow to get the magnesite dissolution rate and average porosity.

For correlation analysis, a regression …

Numerical Analysis Of Flexural Slip During Viscoelastic Buckle Folding, Davi Rodrigues Damasceno

Masters Theses

"Flexural slip is considered to be an important folding mechanism contributing in the development of different folds such as chevron, and kink-band buckle folds. Various filed studies have provided a general conceptual and qualitative understanding of flexural slip. However, quantitative evidence of the importance of the flexural slip mechanism during fold evolution is sparse, as the actual amount of surface parallel displacement, and timing, is difficult to measure accurately, due to the lack of suitable strain markers.

In this study 2D finite element analysis is used to overcome these disadvantages and to simulate flexural slip during viscoelastic buckle folding. Variations …

Effect Of Reservoirs Heterogeneity On Injection Pressure And Placement Of Preformed Particle Gel For Conformance Control, Ze Wang

Masters Theses

"Preformed particle gels (PPG) have been successfully applied as a plugging agent for plugging fractures and then divert displacing fluid into poorly swept zones. However, PPG propagation and plugging mechanisms through open fractures have not been studied thoroughly.

This work investigated the influence of some factors (particle size, brine concentration, heterogeneity, and brine salinity) on gel injectivity, plugging performance for water flow through open fractures. Five-foot tubes were used to mimic open fractures. Three models were designed to conduct the work, including (1) single fracture with uniform fracture width, (2) single fracture with different widths, and (3) two parallel fractures …