Papers by Mohammad Ghafoori
Journal of Petroleum Science and Engineering, 2017
This paper, demonstrated a scientific approach to prepare a geomechanical model for Bangestan res... more This paper, demonstrated a scientific approach to prepare a geomechanical model for Bangestan reservoir in an oil well in the southwest of Iran. Bangestan is one of the most important oil reservoirs in the Middle-East that its geomechanical characters are not perfectly known. Moreover, unexpected problems such as casing collapse, production drop and land subsidence occurred in this reservoir that made it necessary to conduct a comprehensive geomechanical model. According to borehole failure observations from a formation micro scanner (FMS) image log, the direction of minimum and maximum horizontal in-situ stresses (S h and S H) were N35E and N55W, respectively. Also, using poro-elastic formulations, in-situ stress regime was found to be strike-slip (i.e. S H > S v > S h). Besides, the optimum mud weight for safe drilling at borehole breakout based on Mohr-Coulomb and Mogi-Coulomb criteria were found 85.12 and 80.42 pcf, respectively, while 79 pcf had been applied in practice. Finally, the precision of the geomechanical model was evaluated using natural fracture observations in the FMS image logs. The FMS logs revealed a total of 510 natural fractures in five clusters. In case of all fracture intervals, petrophysical properties and in-situ stresses decreased and therefore, the model was adequately sensitive to the fractures.
Engineering Geology, 2002
The Tabarak Abad Dam on the river Tabarak, a branch of Atrak river, is located about 25 km of nor... more The Tabarak Abad Dam on the river Tabarak, a branch of Atrak river, is located about 25 km of northeast of Quchan city in the northeast of Iran. The dam is now under construction and will be completed in 2002. The Tabarak Abad Dam has been designed as an earthfill dam with a clay core. The dam and its associated concrete structures are mainly founded on limestone and shale of the Shoorigeh formation of Upper Jurassic to Lower Cretaceous age and limestone and sandstone of the Tirgan formation of Lower Cretaceous age. These rocks are affected by high jointing and faulting especially in the surface. This paper discusses the site investigation for the dam.
Journal of Biodiversity and Environmental Sciences, Jun 12, 2014
Nowadays in situ geotechnical tests are used by the geotechnical engineers in a variety of forms.... more Nowadays in situ geotechnical tests are used by the geotechnical engineers in a variety of forms. The SPT test, due to the simplicity, low cost, and association with other soil parameters, is using widely in engineering projects. The results of this test are associated with only a point, while the project engineers need information about the whole project area, especially the places with not samples. Therefore, using of geostatistical and interpolation methods to produce maps of soil engineering parameters is very common. In this research, the examined results of SPT in 18 study boreholes within the area of Chehel Baze national park of Mashhad city, according to blows change from 10 to 50, using geostatistical methods and general Kriging tool, the map of SPT changes and the estimation error maps was prepared. According to the results, it seems that geostatistical methods due to the acceptable precision and nature of geotechnical parameters, is a useful tool for predicting the number of SPT for area that tested data is not available.
Indian journal of scientific research, 2014
Comptes Rendus De L Academie Bulgare Des Sciences, 2016
International. Journal of Mining & Geo-Engineering, 2016
Reliable characterization of subsurface soil in urban areas is a major concern in geotechnical an... more Reliable characterization of subsurface soil in urban areas is a major concern in geotechnical and geological engineering projects. In this regard, this research deals with development of a 3D geological engineering model on Mashhad City soil using Sequential Gaussian Simulation (SGS) approach. The intense variability of soil in the study area has sometimes caused serious problems in civil engineering projects in the city. Therefore, a better understanding of these deposits is critical for current and future civil engineering work. The main objectives of this study were investigating the spatial variability of soil through variograms and then predicting the values of soil properties at unsampled locations using SGS method. In this study, some geotechnical index parameters including percentage of fine grained material, plasticity index, and liquid limit have been employed as input data. A database including the data of 1750 boreholes was built and the hard data were transformed into ...
Eighth International Congress, International Association for Engineering Geology and the Environment , 1998-09-21, 1998
Rock Mechanics and Rock Engineering, 2020
One of the main problems related to mature oilfields is the decreased pore pressure due to hydroc... more One of the main problems related to mature oilfields is the decreased pore pressure due to hydrocarbon production. Therefore, to maintain the production rate of a reservoir, the lost pressure must be compensated. A very traditional method to increase the pressure is to inject natural gas into the reservoir. This technique is widely used in SW Iranian reservoirs because of the readily available supply of this type of gas. Reactivation of pre-existing faults and inducing new fractures into the reservoir and cap rock are some of the potential risks regarding gas injection. In this article, using data such as well logs, pore pressure estimates, and rock mechanical test results, the geomechanical simulation of the Asmari reservoir in the Gachsaran oilfield, SW Iran has been carried out. For this purpose, the current stress field was determined using elastic moduli of reservoir rocks and formation integrity test (FIT) results. Then, by applying analytical methods such as Mohr diagrams and slip tendency, the reactivation possibility of four faults in the field was analyzed, and the maximum sustainable pore pressures were estimated. In the next step, numerical simulations were conducted using ABAQUS software to investigate the injected gas flow path, leakage potential through the cap rock, possible fault reactivation due to gas injection, and shear stress build-up and plastic strain development in different parts of the reservoir. Results of Mohr diagrams and slip tendency showed that all the faults are stable in the current stress state, and fault F2 has the potential to sustain a maximum pore pressure of 55 MPa in the field. On the other hand, fault F3 has the proper conditions (i.e., strike and dip referring to σ Hmax orientation) for reactivation. Results of numerical simulations suggested that an injection pressure of 30 MPa would not induce any new fracture or fault slip within 5 years of injection. In this period, the injected gas plume moves upward through the damage zone and reaches the shallower parts of the cap rock. It was also shown that by applying an injection pressure of 60 MPa, slip would occur on fault F4 after 10 days of injection.
Bulletin of Engineering Geology and the Environment, 2017
Gypseous soils are considered problematic when used as the foundation in civil engineering struct... more Gypseous soils are considered problematic when used as the foundation in civil engineering structures such as roads, buildings and dams, due to their solubility. These soils are resistant and have good engineering properties in their dry state. However, when saturated by rainwater or a rising groundwater table, the soluble minerals are washed out, resulting in the subsidence of the structures built on them. In the recent decades, buildings constructed in the Southern Mashhad Metropolitan Area, Iran, have been widely faced with this problem. Since the changes in chemical composition and engineering properties of these soils are based on the amount of dissolved gypsum, the focus of this study is to characterize the soluble soils of this area and their changes throughout the leaching process. Thirty-eight samples were taken from different locations in the area. Chemical tests were conducted on the samples and the gypsum and sulfate concentration maps were produced based on these results, combined with the previously available data from 511 boreholes drilled in the area. Seven soil samples with different gypsum concentrations were selected for further analysis in four major groups of tests, including hydraulic tests (permeability and solubility), chemical tests (chemical analysis of soils samples and total dissolved solids, calcium hardness and chlorine of the leachate samples), physical tests (grain size analysis, Atterberg limits and specific gravity) and mechanical tests (consolidation and direct shear). Changes in the mentioned parameters were investigated through a 5-day leaching process. The results indicate that extensive dissolution of gypsum and removal of gypsum bonding between soil particles change soil chemical composition and decrease the soil compressibility and strength parameters. Therefore, the structures built in this area are in high risk of subsidence and foundation failure; proper measures should be taken to improve the soil quality before construction.
conference.khuisf.ac.ir
Mashhad city has been developed in recent decades. The development of the city towards the routes... more Mashhad city has been developed in recent decades. The development of the city towards the routes used to be qanat well is one of the problems that Mashhad city is confronted. Today many of the qanats are under urban areas. These qanats become dry little by little because of successive droughts, developing of the city and drilling deep wells In order to supply water. Contemporary of developing the city, the qanats are filled with earth fill soils uncontrollably and this problem causes ground settlement, cracks and fissures in the ground and consequently damages of buildings and also cracking in the system of water supply. This problem is doubled in west areas of the city because of high buildings and high abundance of qanats in those areas. This paper deals with the main factors that cause qanat collapse. First of all the exact location of the qanats in the zone11 of municipality of Mashhad was studied. Then the main factors that influence the stability and performance of qanats were determined. These factors include: depth of qanat gallery, loading due to surface structures, land use, underground water table and geotechnical properties of the soil. Finally areas with the most potential of collapse hazard are introduced. The results can be used in planning for increasing the security level of buildings and structures in hazardous areas of the city.
Journal of Economic Geology, 2020
Introduction In the southern margin of the Mashhad plain in Northeastern Iran, there are strips w... more Introduction In the southern margin of the Mashhad plain in Northeastern Iran, there are strips with tens of kilometers length consisting of metamorphic rocks and ophiolite complexes with the NE-SW trend. Ophiolites are fragments of ancient Oceanic crust (Ghaseminejad and Torabi, 2015; Khanchuk et al., 2016; Shirdashtzadeh et al, 2017) most of which consists of ultramafic rocks. Ophiolites are formed during tectonic displacement in the southern part of the Mashhad plain (Alavi, 1991; Karimpour et al., 2010; Sheikholeslami and Kouhpeyma, 2012; Zanchetta et al., 2013; Shafaii Moghadam and Stern, 2014). These undergoing metamorphosed regions ultimately lead to the formation of serpentines complex due to factors of pressure and temperature. Subsequently, tectonic variations create different levels of serpentinization in the region. Different degrees of serpentines have different geotechnical properties that are discussed in this study. Materials and methods To conduct the lithological s...
Ghordanloo dam on the Atrak river, is located about 36 km of northwest of Bojnord city, in the no... more Ghordanloo dam on the Atrak river, is located about 36 km of northwest of Bojnord city, in the northeast of Iran. This dam currently is at the final stage of the study phase and has been designed as an earth dam with clay core. In this study, engineering geological properties of the rock mass at the dam were investigated in order to evaluate engineering geology properties of the rock masses. The lithology of the rock masses consist of Tirgan formation limestone with lower Cretaceous age that outcrops on both abutments. The thickness of alluvial deposit at the dam axis is 61 meters and it consists of river bend of fine grained and coarse grained materials. The rock mass investigation of the site is performed in both filed geology and laboratory studies. Field study includes the analysis of discontinuity system, boreholes exploration, performing permeability test and sample extraction for laboratory studies. The laboratory study consists of performing uniaxial compression test, Young’...
Journal of African Earth Sciences, 2015
Distinctive characteristics of inverted structures make them important criteria for the identific... more Distinctive characteristics of inverted structures make them important criteria for the identification of certain structural styles of folded belts. The interpretation of 3D seismic reflection and well data sheds new light on the structural evolution and age of inverted structures associated to the HendijaneNowrooz eKhafji Fault within the Persian Gulf Basin and northeastern margin of Afro-Arabian plate. Analysis of thickness variations of growth strata using "T-Z plot" (thickness versus throw plot) method revealed the kinematics of the fault. Obtained results show that the fault has experienced a multi-phase evolutionary history over six different extension and compression deformation events (i.e. positive and negative inversion) between 252.2 and 11.62 Ma. This cyclic activity of the growth fault was resulted from alteration of sedimentary processes during continuous fault slip. The structural development of the study area both during positive and negative inversion geometry styles was ultimately controlled by the relative motion between the Afro-Arabian and Central-Iranian plates.
Abstract--Underground excavations in rock are manufactured either by drilling and blasting or by ... more Abstract--Underground excavations in rock are manufactured either by drilling and blasting or by mechanical methods using roadheaders or tunnel boring machines (TBMs). Both methods employ tools which interact with the rock and this interaction leads to the fragmentation of the rock as well as to the wear of the tools. Wear may be defined as the loss of tool material while interacting with the rock. Cerchar abrasiveness test is widely used to assess the abrasiveness of rock to predict of rock cutting tool wear because it provides good information on the abrasiveness with quick and easy testing procedure. Various parameters may affect Cerchar abrasiveness index (CAI), for example, surface condition of rock, mineral contents of rock, etc. In this paper, the relations between geological properties of rock and CAI were examined for several different sandstones. The derivation of some predictive models for the engineering geological properties of sedimentary rocks will be useful due to th...
... 24. Title : ( Sedimentation problem in Tabarak Abad Dam, northeast Iran ). Gholam Reza Lashka... more ... 24. Title : ( Sedimentation problem in Tabarak Abad Dam, northeast Iran ). Gholam Reza Lashkaripour , Mohammad Ghafoori , Full Text. Abstract. Sedimentation problem in Tabarak Abad Dam, northeast Iran. کلمات کلیدی. , sedimentation ...
Carpathian Journal of Earth and Environmental Sciences, 2011
In recent years, dust storms coming from western neighboring countries are drastically increased ... more In recent years, dust storms coming from western neighboring countries are drastically increased dust storms and affecting western and even central part of Iran. This phenomenon is caused a lot of environmental and socio-economic problems. A few studies have been carried out to determine the sources of dusts. Most of them have been done base on satellite images and metrological information which were reviewed in this paper. Geological maps and information on wind erosion susceptible land can help to determine the areas for dust materials producing. In this paper, dust sources which determined by the previous studies were compared by geological unites map and the map of mean annual rainfall of susceptible areas in the western neighboring countries. This research can be help to find the impact of geological units on the wind erosion lands for finding dust storm sources in the states of western parts of Iran.
Article History: Received 6, October, 2014 Received in revised form 17, October, 2014 Accepted 2n... more Article History: Received 6, October, 2014 Received in revised form 17, October, 2014 Accepted 2nd, November, 2014 Published online 28, November, 2014 The seismotectonic provinces are the basis of many seismology studies in a given area. The seismotectonic provinces, in which the seismic activity is distributed homogenously and lay in same tectonically and geologically region, are used as the basic maps in seismology studies and preparation of seismic hazard maps. In the last decays, the seismological studies of the Kurdistan Region (north and northeastern of Iraq) didn’t proceeded well and there are not comprehensive seismicity map and perfect Fault map in this region. Also, there is not efficient Seismotectonic division in Iraq, as well as in Kurdistan Region. The study area encompassed by the 40.50–47.50°E longitudes and 33.50– 39.50°N latitudes. This research reviews the structural zones, tectonics and neotectonics, fault map and finally the seismicity of area to delineate the s...
Soil liquefaction is among the secondary earthquake effects. This phenomenon, which was widely se... more Soil liquefaction is among the secondary earthquake effects. This phenomenon, which was widely seen in Astaneh-ye Ashrafiyeh during the 1990 Manjil-Rudbar earthquake, led to considerable damage. The present study was conducted to assess the future re-liquefaction hazard and risk and prepare liquefaction hazard map of the study area. For this purpose, in addition to the available geotechnical data, 20 new boreholes were excavated and both in site and laboratory experiments were conducted on 100 soil samples. To prepare liquefaction risk zonation map, the structural condition and the value of 1,000 residential and commercial units, and lifelines were evaluated. Next, using the risk matrix model, the risk map of the Astaneh-ye Ashrafiyeh City was prepared. The results show that although liquefaction history of the area has reduced liquefaction risk in some parts of the city, the risk was increased in the central parts of the city due to the traditional texture of the city and dense bui...
One of the tests that used for the characterization of soil abrasivity, is LCPC test. LCPC test d... more One of the tests that used for the characterization of soil abrasivity, is LCPC test. LCPC test device is designed for measuring the wear particles as small as pebbles (4-6.3 mm). In this study, three most important abrasive minerals were collected for analyzing the effect of the geological parameters on the ability of abrasive minerals. Firstly, amount of index minerals abrasivity is measured according to three standards of AFNOR P18-553, AFNOR P18-579 and AFNOR P18-560 that are the preparation of samples for testing, procedure of laboratory tests and analysis of grain size with laboratory sieves. The effect of geological parameters affecting the wear rate of the sample, including five parameters of shape, size, angularity and saturation rate of the environment, has been studied. The effectiveness of these parameters on the abrasivity of samples are studied according to NF ISO 5725 relating to usage of statistics, the accuracy of test method, the repeatability and the ability to re...
In the past, many underground water channel systems (Qanats) were used to extraction of groundwat... more In the past, many underground water channel systems (Qanats) were used to extraction of groundwater in Mashhad and its surrounding area. Nowadays, most of them have dried out and the city has developed on them. The constructions of tall buildings in recent years increase the potential of Qanats collapsibility in this area. In this paper the distribution of Qantas system in West of Mashhad and their stability's under different loading and support system conditions are investigated. For this, the locations of Qanats wells are mapped using the aerial photograph then the roughly depth of Qanats are estimated based on the few site measurements and existing documents. The stability of Qanats was evaluated based on the elasto-plastic soil models in four depth and different support systems. The results have shown that with increase of Qanat depth the extension rate of plastic zone decreases. Also the effect of the support covers in the plastic zone decrease with increasing the Qanat dep...
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Papers by Mohammad Ghafoori