scholarly journals Initial exploration of Hydrocarbon resources by Gravity Data: A Case Study in the South of Qom Province, Iran

2015 ◽  
Vol 2 (1) ◽  
pp. 52-57
Author(s):  
Payam Salimi

Geophysical methods widely used in oil and gas exploration. Modeling of gravity data is used extensively to illustrate the geometry and interface between the sediments and bedrock. Which can help the salt dome, anticline folds, dome-shaped uplift of the continental platform and reef masses to be identified. There are various methods to illustrate the bedrock topography, and we will describe one of these methods in present paper. Using the upward continuation, we extract the residual gravity anomaly which in fact shows the local effect of bedrock gravity on the observed gravity. Then, according to the Oldenburg - Parker method, the residual gravity data are inversed and finally the 3D geometry the bedrock is illustrated. It should be noted that some software's like Surfer and Excel are used in this research but the program main code is written using Matlab programming.

2021 ◽  
pp. 1-45
Author(s):  
Qin Su ◽  
Huahui Zeng ◽  
Yancan Tian ◽  
HaiLiang Li ◽  
Lei Lyu ◽  
...  

Seismic processing and interpretation techniques provide important tools for the oil and gas exploration of the Songliao Basin in eastern China, which is dominated by terrestrial facies. In the Songliao Basin, a large number of thin-sand reservoirs are widely distributed, which are the primary targets of potential oil and gas exploration and exploitation. An important job of the exploration in the Songliao Basin is to accurately describe the distribution of these thin-sand belts and the sand-body shapes. However, the thickness of these thin-sand reservoirs are generally below the resolution of the conventional seismic processing. Most of the reservoirs are thin-interbeds of sand and mudstones with strong vertical and lateral variations. This makes it difficult to accurately predict the vertical and horizontal distribution of the thin-sand bodies using the conventional seismic processing and interpretation methods. Additionally, these lithologic traps are difficult to identify due to the complex controlling factor and distribution characteristics, and strong concealment. These challenges motivate us to improve the seismic data quality to help delineate the thin-sand reservoirs. In this paper, we use the broadband, wide-azimuth, and high-density integrated seismic exploration technique to help delineate the thin-reservoirs. We first use field single-point excitation and single-point receiver acquisition to obtain seismic data with wide frequency-bands, wide-azimuth angles, and high folds, which contain rich geological information. Next, we perform the near-surface Q-compensation, viscoelastic prestack time migration, seismic attributes, and seismic waveform indication inversion on the new acquired seismic data. The 3D case study indicates the benefits of improving the imaging of thin-sand body and the accuracy of inversion and reservoir characterization using the method in this paper.


2018 ◽  
Vol 6 (2) ◽  
pp. T431-T447 ◽  
Author(s):  
Xiaoming Sun ◽  
Siyuan Cao ◽  
Xiao Pan ◽  
Xiangyang Hou ◽  
Hui Gao ◽  
...  

Volcanic reservoirs have been overlooked for hydrocarbon exploration for a long time. Carboniferous volcanic rocks of the Zhongguai paleouplift contain proven reserves of [Formula: see text]. We have investigated the volcanic reservoirs integrating cores, well, and seismic data, and the proposed volcanic reservoir distribution is controlled by the weathering function, fractures, and lithology. The weathering process makes the originally tight igneous rocks become good-quality reservoirs, and fractures play an important role in connecting different types of pores and act as reservoir space. Isolated and ineffective pores become effective ones due to connection among fractures. Only volcanic breccia can be good-quality reservoirs without any weathering function. The nonlinear chaos inversion controlled by weathered layers shows that the good-quality reservoirs are distributed in the top of the weathering crust and the structural high. Furthermore, fluid-detection attributes and background information prove that oil and gas are distributed along the paleostructural high. The objectives of this study were to (1) describe the characteristics of volcanic reservoirs and determine the controlled rules for reservoir distribution, (2) characterize the distribution of reservoirs and hydrocarbon, and (3) propose an effective workflow for hydrocarbon exploration in volcanic rocks combining geologic and geophysical methods.


2021 ◽  
Vol 2 (3) ◽  
pp. 55-60
Author(s):  
Ekaterina E. Khogoeva ◽  
Evgeny A. Khogoev

This study is devoted to an analysis of microseisms registered on gas-condensate field area. Presence of seismic emission effect on a part of the area is demonstrated. A microseismic anomaly is outlined in NW part of the area and proves correct by 3 seismic CDP profiles and interpreted as a reservoir. The results of the special processing was compared to the results of a set of other geophysical methods. Correlation between the found anomaly and an anomaly found with aerogamma-specrtometry is shown. The results can be used in an integrated interpretation of geophysical data for oil and gas reservoirs of both structural as nonstructural types.


GEODYNAMICS ◽  
2011 ◽  
Vol 2(11)2011 (2(11)) ◽  
pp. 158-160
Author(s):  
S. P. Levashov ◽  
◽  
M. A. Yakymchuk ◽  
I. M. Korchahin ◽  
◽  
...  

The mobile geophysical technology include a special method of the remote sensing data processing and interpreting, aerial mapping method of the forming short-pulsed electromagnetic field (FSPEF), method of vertical electric-resonance sounding (VERS). Inclusion of such technologies in traditional complex of exploration geological-geophysical methods will promote both minimization of the financial expenses on the oil-and-gas exploration problems solving, and essential reduction of time for their practical realization.


Geophysics ◽  
2020 ◽  
Vol 85 (3) ◽  
pp. G69-G80
Author(s):  
Zhiming Xiong ◽  
Juliang Cao ◽  
Kaixun Liao ◽  
Meiping Wu ◽  
Shaokun Cai ◽  
...  

Underwater gravity information plays a major role in deepwater oil and gas exploration. To realize underwater dynamic gravimetry, we have developed a strapdown gravimeter mounted in a pressure capsule for adaption to the underwater environment and we adopted a two-stage towed underwater gravimetry scheme. An improved strapdown gravimeter and other underwater sensors were installed in a towed vessel to form an underwater dynamic gravimetry system. Because the global navigation satellite system cannot be used for underwater dynamic gravimetry, we developed a new method based on underwater multisensor integrated navigation, in which a federal Kalman filter was applied for error estimation. This new method allowed us to obtain the accurate attitude, velocity, and position necessary for gravity estimation. In addition, the gravity data can then be extracted from the noisy data through finite impulse response low-pass filtering. We acquired the underwater gravity data at a depth of 300 m to test the validity of the new method and evaluate the accuracy of the underwater gravity system. The results indicated a repeatability from 0.85 to 0.96 mGal at a half wavelength of approximately 0.2 km and also indicated good consistency with the marine gravity data.


2020 ◽  
Vol 8 (4) ◽  
pp. SQ15-SQ24
Author(s):  
Christian H. Henke ◽  
Markus H. Krieger ◽  
Kurt Strack ◽  
Andrea Zerilli

Imaging subsalt is still a challenging task in oil and gas exploration. We have used magnetotellurics (MT) to improve the integration of seismic and gravity data to image the Wedehof salt dome, located in the Northern German Basin. High-density natural field source broadband MT data were acquired and enhanced the definition of the top and overhanging salt structures in addition to imaging the salt dome root. Salt boundaries show strong resistivity contrasts with the surrounding sediments and thus represent a good target for electromagnetic measurements, especially for top salt and salt flanks imaging. With integrated 3D gravity modeling focusing on the salt dome’s flanks at intermediate depths, an improved model was achieved. The new model provided sound input to a follow-up seismic depth migration that led to an improved imaging of the subsalt target proven by subsequent exploration drilling. The integrated interpretation of MT, gravity, and seismic combines the strengths of the different physics, thus increasing imaging reliability and reducing exploration drilling risks. Using a conservative workflow that included a feasibility study with field noise evaluation and careful acquisition parameter testing prior to survey start, a broadband array data acquisition, and advanced processing, the survey area's severe cultural noise issues could be overcome.


Geophysics ◽  
1953 ◽  
Vol 18 (2) ◽  
pp. 340-359 ◽  
Author(s):  
Robert B. Baum

The discovery of the Pollard oil field in southern Alabama early in 1952 sparked a campaign of leasing and exploration which spread quickly into Georgia and Florida. Three fields in southwestern Alabama and one in southern Florida account for all the oil production in the three states. Some aspects of the general geology and geophysics of the area, illustrated with maps, cross sections, and correlation charts, suggest the presence of geologic conditions favorable for the possible trapping and accumulation of oil and gas. Early seismograph exploration in much of the area was not effective, but in recent months the tempo of seismic activity has been accelerating, and improvements in instrumental and interpretive techniques are being achieved through current experimental work. The use of the various geophysical methods contributed to the discovery of the four oil fields located in the area. The structural traps indicated by the contour maps of the four fields are of the type sought by the reflection seismic method. Examples of representative reflection records indicate the presence of usable and correlatable seismic events. A seismic cross section prepared from data of this type shows the fault zone associated with the Pollard field. The existence of favorable geologic conditions in the southeastern states and the recent oil field successes at Pollard and South Carlton indicate the continuing of active development and exploration throughout the area.


Author(s):  
Maulana Rizki Aditama ◽  
Huzaely Latief Sunan ◽  
FX Anjar Tri Laksono ◽  
Gumilar Ramadhan ◽  
Sachrul Iswahyudi ◽  
...  

The thickness of the liquefable layer can be the factor inducing liquefaction hazard, apart from seismicity. Several studies have been conducted to predict the possibility of the liquefable layer based on the filed sampling. However, a detailed investigation of the subsurface interpretation has not been defined, in particular the thickness estimation of the liquefable layer. This study is carried out in south Cilacap area where potential liquefaction is exists due to the earthquake history data and near surface condition. The aim of this study is to investigate the physical properties and thickness distribution using GGMplus gravity data and resistivity data. This research is conducted by spectrum analysis of gravity model and 2D resistivity model . This study’s main results is by performing the residual gravity anomaly with the associated SRTM/DEM data to define the subsurface physical distribution and structural orientation of the area. Residual gravity anomaly is also separated through the low pass filter in order to have robust interpretation. The residual anomaly indicates that the area has identical structural pattern with geological and SRTM map. The results show a pattern of high gravity index in the northeast area of ​​the study having range of 70 – 115 MGal gravity index, associated with the volcanic breccia, and a low gravity profile with less than 65 in the southwest, associated with the alluvial and water table dominated distribution. The thickness of Alluvial is determined by resistivity model with H1 at a range of 3 meters and H2 at a range of 4 m. This research is included in the potential liquefaction category with the potential for a large earthquake.


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