Identification of fractured carbonate vuggy reservoirs in the S48 well area using 3D 3C seismic technique: A case history from the Tarim Basin

Geophysics ◽  
2019 ◽  
Vol 84 (1) ◽  
pp. B59-B74 ◽  
Author(s):  
Zongjie Li ◽  
Yun Wang ◽  
Zichuan Yang ◽  
Haiying Li ◽  
Guangming Yu
Keyword(s):  
Tarim Basin ◽  
Seismic Data ◽  
Gas Production ◽  
Carbonate Reservoir ◽  
Seismic Exploration ◽  
Fractured Carbonate ◽  
Seismic Acquisition ◽  
And Migration ◽  
Fluid Detection ◽  
Oil Gas

As a type of carbonate reservoir and main oil-gas production formation in the Tarim Basin, China, fractures and paleokarst caves in Ordovician limestone are the targets of interest for seismic exploration in the S48 well area. Although conventional 3D, high-density, and wide-azimuth seismic acquisition has been widely applied in the Tarim Basin, we still need to determine what 3D 3C seismic data can further do for the characterization and fluid detection of the carbonate reservoir. In the S48 well area of the Tahe oilfield, we had acquired 3D 3C seismic data with single digital 3C sensors at the same grid, whereas the traditional 1C acquisition had arrayed geophones. Through comparison and analysis of two kinds of seismic data, including field records and migration profiles, some important characteristics can be found: (1) The [Formula: see text]

Successfully Controlling Unwanted Gas Production in a Highly Naturally Fractured Carbonate Reservoir

2011 ◽  
Author(s):  
Ismael Diaz ◽  
Tomas Nava ◽  
Carlos Deolarte ◽  
Oscar Castillo ◽  
Julio Vasquez ◽  
...  
Keyword(s):  
Gas Production ◽  
Carbonate Reservoir ◽  
Naturally Fractured ◽  
Fractured Carbonate

Wavelet Basis Function Optimization and its Application in Carbonate Reservoir Fluid Detection

2013 ◽  
Vol 318 ◽  
pp. 263-266 ◽  
Author(s):  
Hui Qun Xu ◽  
Zhi Xian Gui
Keyword(s):  
Basis Function ◽  
Seismic Data ◽  
Carbonate Reservoir ◽  
Function Optimization ◽  
Wavelet Basis ◽  
Base Function ◽  
Time Frequency ◽  
Amplitude Anomaly ◽  
Strong Amplitude ◽  
Fluid Detection

he purpose of this paper was to perform optimize the best wavelet basis function and TFA (Time frequency analysis) techniques on a target, in order to provide high-resolution instant spectrum data to help in the fluid detection. Wavelet transform is an effective tool to calculate the frequency. And spectral decomposition technique can depict the frequency characters of seismic reflection that are caused by fluid. In order to optimize the best wavelet basis function, different wavelet basis was tested on a sin model to determine the optimum parameters on the noised-sinusoidal model. Several wavelet bases were tested for the frequency recognition capability on the model, and then the optimum wavelet base function was used in the subset of the seismic data. The optimal wavelet basis was selected to test in the subset of the seismic data, strong amplitude anomaly showed. And so may be use the well-log interpretation result to guarantee that the strong amplitude anomaly have effects at the target.

AVO detectability against tuning and stretching artifacts

Geophysics ◽  
1999 ◽  
Vol 64 (2) ◽  
pp. 494-503 ◽  
Author(s):  
Wenjie Dong
Keyword(s):  
Seismic Data ◽  
Synthetic Data ◽  
Seismic Exploration ◽  
Inversion Algorithm ◽  
Amplitude Variation With Offset ◽  
Logical Point ◽  
Anomalous Reflection ◽  
Ricker Wavelet ◽  
And Migration ◽  
And Inversion

The [Formula: see text] of hydrocarbon‐bearing sediments normally deviates from the [Formula: see text] trend of the background rocks. This causes anomalous reflection amplitude variation with offset (AVO) in the seismic data. The estimation of these AVOs is inevitably affected by wave propagation effects and inversion algorithm limitations, such as thin‐bed tuning and migration stretch. A logical point is to determine the minimum [Formula: see text] change required for an anomalous AVO to be detectable beyond the background tuning and stretching effects. Assuming Ricker wavelet for the seismic data, this study addresses this point by quantifying the errors in the intercept/slope estimate. Using these results, two detectability conditions are derived. Denoting the background [Formula: see text] by γ and its variation by δγ, the thin‐bed parameter (thickness/wavelength) by ξ, the maximum background intercept closest to the AVO by |A|max, and the thin‐bed intercept value by |A|thin the two conditions are [Formula: see text] [Formula: see text] for detectability against stretching and tuning plus stretching, respectively. Tests on synthetic data confirm their validity and accuracy. These conditions provide a quantitative guideline for evaluating AVO applicability and effectiveness in seismic exploration. They can eliminate some of the subjectivity when interpreting AVO results in different attribute spaces. To improve AVO detectability, a procedure is suggested for removing the tuning and stretching effects.

scholarly journals Development of a New Centralized Data Acquisition System for Seismic Exploration

2019 ◽  
Author(s):  
Feng Guo ◽  
Qisheng Zhang ◽  
Qimao Zhang ◽  
Wenhao Li ◽  
Yueyun Luo ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Seismic Data ◽  
Dynamic Range ◽  
Sampling Rate ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Seismic Exploration ◽  
Seismic Data Acquisition ◽  
Electrical Prospecting ◽  
And Migration

Abstract. Seismic exploration equipment has developed rapidly over the past few decades. One such piece of equipment is a centralized seismograph, which plays an important role in engineering, so improving its performance is of great scientific significance. However, there is still a gap between seismic exploration equipment that is inde-pendently developed by China and that developed worldwide; this gap needs to be bridged via the advancements made in technology. In this research, the core part of general seismic data acquisition devices is packaged to develop a centralized seismic data acquisition system (Named as CUGB-CS48DAS) that has independent operating ability and high scalability, which can be used for engineering seismic and electrical prospecting. The low-power-consumption computer of the system comprises a 24-bit Σ-△ modulation A/D converter and 48 sampling channels with an optional sampling rate of 50 Hz to 64 KHz, crosstalk rejection ratio ≥ 80 dB, dynamic range ≥ 120 dB, frequency response range of DC to 16 KHz, synchronization accuracy better than 200 ns, and data transmission speed ≥ 90 Mbps. With regard to the host computer, the ar-chitecture of the control software is smart, and it can integrate the multiple functions of data acquisition, preprocessing, and self-testing; clear interfaces reduce the com-plexity of development and migration.

Innovative Solutions to Fines Management in High Permeability Sands

2007 ◽  
Vol 18-19 ◽  
pp. 287-292
Author(s):  
Babs Mufutau Oyeneyin ◽  
Said Mufarji ◽  
Donald Igwegbu
Keyword(s):  
Gas Production ◽  
Operating Conditions ◽  
Maintenance Cost ◽  
High Permeability ◽  
Two Phase ◽  
Fines Migration ◽  
Blocking Mechanisms ◽  
Core Flood ◽  
And Migration ◽  
Oil Gas

Formation impairment due to fines migration during drilling and production continues to cause injectivity or inflow reduction. In high permeability sandstone formations or sandpacks, fines migration pose major concerns in the oil industry as it leads to reduction in oil/gas production. The problem is further enhanced in mature reservoirs where increased water ingress and multiphase production aggravate the fines mobilisation and migration. Proper fines management can optimise productivity, safeguard facilities and reduce well maintenance cost. Today’s core flood tests as part of risk assessment limit tests to single phase or at best two-phase oil/water flow. This paper presents the unique technique adopted to analyse fines migration mechanisms in a true multiphase environment. The technique integrates CFD and 3-D reservoir simulation concepts to define and quantify the effects of different operating conditions on discretised reservoir blocks. From the results obtained detailed mapping of prevailing pore blocking mechanisms and corresponding impairment profiles are presented as functions of operating conditions and completion strategies. The paper introduces a parallel experimental programme being initiated at The Robert Gordon University(RGU) to validate the simulation predictions. The paper is concluded with suggestions (supported by flow efficiency case studies) on contemporary innovations in fines management ranging from a radical use of expandable screens (ESSTM) or expandable slotted liners (ESLTM) or the intelligent VSSTM Screen to specialist application of glass or ceramic beads for pore diameter control and near wellbore reinforcement to initiate secondary filtration

scholarly journals Investigation of geophysical challenges in land seismic data acquisition in Nigeria: case study of parts of the Niger Delta region

2021 ◽  
Vol 11 (2) ◽  
pp. 587-599
Author(s):  
C. N. Onwubuariri ◽  
L. S. Al-Naimi ◽  
B. I. Ijeh ◽  
T. I. Mgbeojedo ◽  
M. U. Igboekwe ◽  
...  
Keyword(s):  
Seismic Data ◽  
Niger Delta ◽  
Weather Conditions ◽  
Seismic Exploration ◽  
Noise Interference ◽  
Niger Delta Region ◽  
Cloudy Weather ◽  
Seismic Acquisition ◽  
Seismic Data Acquisition

AbstractGeophysical analysis was carried out to evaluate the challenges encountered in land seismic exploration within the study area. This analysis cuts across various stages in land seismic acquisition. These stages include the following: the availability of the prospect map as originally planned by the prospect owners—the client, the desk study and planning of this map by the seismology section (planning seismologist) for acquisition convenience and the field implementation of the acquisition which the survey, drill and recording (preloading, shooting, swath move, line check, LAUX crew and recording platform) sections carried out. The challenges observed included environmental challenges, noise interference, weather conditions (statics or electrostatics interference), line break, faulty equipment, wrong detailing, cake or expired explosives, poor or compromised supervision, security and permit challenges. These challenges are peculiar to Nigeria due to inadequate implementation of policies that guide human settlements and activities. Nigeria is within the climate region where most at times it is very impossible to control natural events like cloudy weather, rainfall, thundering and lightening. As such, the problem of static charges interfering with acquired seismic data becomes inevitable, mostly during the rainy season. Almost total dependency on imported technology and lack of readily available experienced manpower also contribute to these challenges, most especially when it has to do with proper inspection of equipment and materials required for the acquisition and supervision processes. Approaches to follow to minimize the observed challenges were equally highlighted.

A Case Study of Complex Carbonate Reservoir Connectivity Analysis, Tarim Basin, China

2021 ◽  
pp. 1-41
Author(s):  
Zhangwu Meng ◽  
Zandong Sun ◽  
Guofa Li
Keyword(s):  
Tarim Basin ◽  
Seismic Data ◽  
Seismic Reflection ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Connectivity Analysis ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Diffraction Imaging ◽  
Reservoir Connectivity

The connectivity of complex carbonate reservoirs has an essential impact on the exploration and development of these reservoirs. From geological genesis, the connectivity of complex carbonate reservoirs is mainly controlled by faults and dissolution. Therefore, accurate identification of faults and karst caves is the key to studying reservoir connectivity. The Ordovician carbonate reservoir in the Hudson Oilfield of the Tarim Basin is used for the reservoir connectivity analysis study. Firstly, we calculate the coherence and curvature attributes and then merge the two attributes using a neural network algorithm. Finally, we use the ant tracking method to track the faults for the merged data. The results show that the approach substantially enhances deterministic faults that can be seen directly on the seismic data, and the subtle faults can also be identified. For reservoir identification, we use the diffraction imaging method to describe the karst reservoir in this study area. The results show that diffraction imaging can identify small-scale caves that cannot be well recognized on the seismic reflection data. Furthermore, the caves connected on the diffraction seismic data are isolated from each other on the seismic reflection data, making the connection between caves clearer. Based on the results of faults and caves identification, we analyze the reservoir connectivity of the study area using the oil pressure and daily production data. It indicates that the NNW and near-NS faults probably play a role in the connection of the reservoirs, while the NEE faults tend to block the connection of the reservoirs.

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