A coupled geomechanical reservoir simulation analysis of CO₂ - EOR: A case study

Elyasi, Ayub,Goshtasbi, Kamran,Hashemolhosseini, Hamid Techno-Press 2016 Geomechanics & engineering Vol.10 No.4

Currently, there is a great interest in the coupling between multiphase fluid flow and geomechanical effects in hydrocarbon reservoirs and surrounding rocks. The ideal solution for this coupled problem is to introduce the geomechanical effects through the stress analysis solution and implement an algorithm, which assures that the equations governing the flow and stress analyses are obeyed in each time step. This paper deals with the implementation of a program (FORTRAN90 interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators, using a partial coupling algorithm. The explicit coupled hydro-mechanical behavior of Iranian field during depletion and $CO_2$ injection is studied using the soils consolidation procedure available in ABAQUS. Time dependent reservoir pressure fields obtained from three dimensional compositional reservoir models were transferred into finite element reservoir geomechanical models in ABAQUS as multi-phase flow in deforming reservoirs cannot be performed within ABAQUS. The FEM analysis of the reservoir showed no sign of plastic strain under production and $CO_2$ injection scenarios in any part of the reservoir and the stress paths do not show a critical behavior.

The impact of sidetracking on the wellbore stability

Elyasi, Ayub,Goshtasbi, Kamran Techno-Press 2015 Advances in energy research Vol.3 No.1

In the past sidetracking was the means to bypass a damaged zone or to correct the direction of a wellbore. Nowadays, this method is very common and useful in relocating the bottom of a wellbore in a more productive zone and consequently enhancing the production of a reservoir by saving a significant amount of time and money. In this paper, the stability of the bend area is assessed considering varied conditions of stress regime and sidetrack orientation. In general, the stress regime and the orientation of the principal stresses have negligible effect on the stability of the sidetrack compared to sidetrack inclination. On the other hand, the sidetrack deviation angle from the vertical main well plays the major role in the stability of the bend area.

Coupled solid and fluid mechanics simulation for estimating optimum injection pressure during reservoir CO2-EOR

Ayub Elyasi,Kamran Goshtasbi,Hamid Hashemolhosseini,Sharif Barati 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.59 No.1

Reservoir geomechanics can play an important role in hydrocarbon recovery mechanism. In CO2-EOR process, reservoir geomechanics analysis is concerned with the simultaneous study of fluid flow and the mechanical response of the reservoir under CO2 injection. Accurate prediction of geomechanical effects during CO2 injection will assist in modeling the Carbon dioxide recovery process and making a better design of process and production equipment. This paper deals with the implementation of a program (FORTRAN 90 interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators, using a partial coupling algorithm. A geomechanics reservoir partially coupled approach is presented that allows to iteratively take the impact of geomechanics into account in the fluid flow calculations and therefore performs a better prediction of the process. The proposed approach is illustrated on a realistic field case. The reservoir geomechanics coupled models show that in the case of lower maximum bottom hole injection pressure, the cumulative oil production is more than other scenarios. Moreover at the high injection pressures, the production rates will not change with the injection bottom hole pressure variations. Also the FEM analysis of the reservoir showed that at CO2 injection pressure of 11000 Psi the plastic strain has been occurred in the some parts of the reservoir and the related stress path show a critical behavior.

Efficiency assessment of L-profiles and pipe fore-poling pre- support systems in difficult geological conditions: a case study

Ayub Elyasi,Taher Moradi,Javad Moharrami,Saeid Parnian,Akbar Mousazadeh,Sepideh Nasseh 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.57 No.6

Tunneling is one of the challenging tasks in civil engineering because it involves a variety of decision making and engineering judgment based on knowledge and experience. One of the challenges is to construct tunnels in risky areas under shallow overburden. In order to prevent the collapse of ceilings and walls of a large tunnels, in such conditions, either a sequential excavation method (SEM) or ground reinforcing method, or a combination of both, can be utilized. This research deals with the numerical modeling of L-profiles and pipe fore-poling pre-support systems in the adit tunnel in northwestern Iran. The first part of the adit tunnel has been drilled in alluvial material with very weak geotechnical parameters. Despite applying an SEM in constructing this tunnel, analyzing the results of numerical modeling done using FLAC3D, as well as observations during drilling, indicate the tunnel instability. To improve operational safety and to prevent collapse, pre-support systems, including pipe fore-poling and L-profiles were designed and implemented. The results of the numerical modeling coupled with monitoring during operation, as well as the results of instrumentation, indicate the efficacy of both these methods in tunnel collapse prevention. Moreover, the results of modeling using FLAC3D and SECTION BUILDER suggest a double angle with equal legs (2L100×100×10 mm) in both box profile and tee array as an alternative section to pipe fore-poling system while neither L80×80×8 mm nor 2L80×80×8 mm can sustain the axial and shear stresses exerted on pipe fore-poling system.

Wear assessment of the WC/Co cemented carbidetricone drillbits in an open pit mine

Saeidi, Omid,Elyasi, Ayub,Torabi, Seyed Rahman Techno-Press 2015 Geomechanics & engineering Vol.8 No.4

In rock drilling, the most important characteristic to clarify is the wear of the drill bits. The reason that the rock drill bits fail with time is wear. In dry sliding contact adhesive wear deteriorates the materials in contact, quickly, and is the result of shear fracture in the momentary contact joins between the surfaces. This paper aims at presenting an overview of the assessment of WC/Co cemented carbide (CC) tricone bit in rotary drilling. To study wear of these bits, two approaches have been used in this research. Firstly, the new bits were weighted before they mounted on the drill rigs and also after completion their useful life to obtain bit weight loss percentage. The characteristics of the rock types drilled by using such this bit were measured, simultaneously. Alternatively, to measure contact wear, namely, matrix wear a micrometer has been used with a resolution of 0.02 mm at different direction on the tricone bits. Equivalent quartz content (EQC), net quartz content (QC), muscovite content (Mu), coarseness index (CI) of drill cuttings and compressive strength of rocks (UCS) were obtained along with thin sections to investigate mineralogical properties in detail. The correlation between effective parameters and bit wear were obtained as result of this study. It was observed that UCS shows no significant correlation with bit wear. By increasing CI and cutting size of rocks wear of bit increases.

The effect of a support program on the burden of spouses caring for their partners with breast cancer: a randomized controlled trial

Seyedeh-Zeynab Hosseinnejad,Forouzan Elyasi,Seyed-Nouraddin Mousavinasab,Zohreh Shahhosseini 대한산부인과학회 2022 Obstetrics & Gynecology Science Vol.65 No.5

ObjectiveThis study aimed to determine the effect of a support program on burden of spouses caring for their partners withbreast cancer. MethodsThis randomized controlled trial was conducted among spouses of women with breast cancer undergoingchemotherapy at a referral chemotherapy center in Iran. They were assigned to intervention (n=40) and control (n=40)groups using permuted block randomization. Three small group sessions lasted 45-60 minutes, followed by threetelephone-based sessions, lasting 15-20 minutes (twice a week). The intervention sessions included defining stressmanagement strategies in different situations: strengthening creativity, optimism, and management in planning,and defining the role of the caregiver. Primary outcome was care burden, and secondary outcomes were spouses’stress, satisfaction with intervention, and partners’ quality of life (QOL). The caregiver burden inventory, depressionanxiety stress questionnaire, World Health Organization QOL brief version, and client satisfaction questionnaire werecompleted before and after the intervention and at a 6-week follow-up. ResultsThirty-eight participants in each group with a mean age of 44.24±9.01 years completed the study. Repeated measuresanalysis of variance showed a significant difference in the care burden (P<0.05; effect size, 0.70), stress (P<0.05; effectsize, 0.64), and women’s QOL (P<0.05; effect size, 0.67) before and after the intervention. ConclusionThe results of this study can be used to develop interventions, targeting the care burden and stress of spouses ofwomen with breast cancer undergoing chemotherapy.

Associations between body dysmorphic disorder (BDD) with the dental health component of the index of orthodontic treatment need (IOTN-DHC) and other BDD risk factors in orthodontic patients: A preliminary study

Farhad Sobouti,Foruzan Elyasi,Reza Alizadeh Navaei,Farbod Rayatnia,Nika Rezaei Kalantari,Sepideh Dadgar,Vahid Rakhshan 대한치과교정학회 2023 대한치과교정학회지 Vol.53 No.1

Objective: Body dysmorphic disorder (BDD) is a form of obsessive-compulsive disorder that may be negatively associated with the self-image. It might be associated with orthodontic treatment demand and outcome, and therefore is important. Thus, this study was conducted. Methods: The Yale-Brown Obsessive-Compulsive Scale modified for Body Dysmorphic Disorder (BDD-YBOCS) questionnaire was used in 699 orthodontic patients above 12 years of age (222 males, 477 females), at seven clinics in two cities (2020–2021). BDD diagnosis and severity were calculated based on the first 3 items and all 12 items of the questionnaire. The dental health component of the index of orthodontic treatment need (IOTN-DHC) was assessed by orthodontists. Multivariable and bivariable statistical analyses were performed on ordinal and dichotomized BDD diagnoses to assess potentially associated factors (IOTN-DHC, age, sex, marital status, education level, and previous orthodontic consultation) (α = 0.05). Results: IOTN-DHC scores 1–5 were seen in 13.0%, 39.9%, 29.8%, 12.4%, and 4.9% of patients. Age/sex/marital status/education were not associated with IOTN-DHC (p > 0.05). Based on 3-item questionnaire, 17.02% of patients had BDD (14.02% mild). Based on 12-item questionnaire, 2.86% had BDD. BDD was more prevalent or severer in females, married patients, patients with a previous history of orthodontic consultation, and patients with milder IOTN-DHCs (p < 0.05). Conclusions: IOTN-DHC was negatively/slightly associated with BDD in orthodontic patients. Being female and married may increase BDD risk.

Improving body image and sexual life among postpartum women: a single-blind-randomized controlled trial to evaluate a social network-based cognitive-behavioral intervention

Erfaneh Talebi,Mohammad Heidari,Forouzan Elyasi,Shayesteh Jahanfar,Zohreh Shahhosseini 대한산부인과학회 2022 Obstetrics & Gynecology Science Vol.65 No.6

ObjectiveTo determine the effect of a social network-based cognitive-behavioral intervention on postpartum body image andsexual life of primiparous women. MethodsIn this single-blind randomized controlled trial, 82 postpartum women were allocated into two intervention andcontrol groups (allocation ratio, 1:1) using permuted block randomization. Primary outcome was change in bodyimage scores between the groups over time. Secondary outcomes were genital self-image, sexual quality of life, andsexual satisfaction. The intervention group participated in eight (2 weeks) 60-minute sessions through WhatsApp(WhatsApp Inc., Mountain View, CA, USA). Data were collected at recruitment, post-intervention, and 1-month offollow-up. ResultsCognitive-behavioral intervention had a medium effect on improving body image in postpartum women (partial etasquared, 0.33; P<0.001). The results showed significant differences between the two groups regarding sexual qualityof life and sexual satisfaction at 1-month follow-up. ConclusionThe results of this study can be used to develop psychological interventions targeting body image in postpartumwomen.