Acquisition and Processing of Shallow Water 3-D Seismic Surveys Over Producing Fields in the Northwest Niger Delta

1989 ◽  
Author(s):  
D.K. Olofin ◽  
R.A. Will
Keyword(s):  
Shallow Water ◽  
Niger Delta ◽  
Seismic Surveys

scholarly journals Delineation of Weathered Layer Using Uphole and Surface Seismic Refraction Methods in Parts of Niger Delta, Nigeria

2021 ◽  
Vol 26 (1) ◽  
pp. 58-66
Author(s):  
Mfoniso Aka ◽  
Okechukwu Agbasi
Keyword(s):  
Niger Delta ◽  
Average Velocity ◽  
Seismic Refraction ◽  
Low Velocity ◽  
Engineering Structures ◽  
Experimental Proof ◽  
Seismic Surveys ◽  
Shot Point ◽  
Weathered Layer ◽  
Velocity Zone

Uphole and surface seismic refraction surveys were carried out in parts of the Niger Delta, Nigeria, to delineate weathering thickness and velocity associated with aweathered layer. A total of twelve uphole and surface seismic refraction surveyswere shot, computed and analyzed. The velocity of the uphole seismic refraction ranged from 344.8 to 680.3 m/s with a thickness of 5.45 to 13.35 m. Surface seismic refraction ranged from 326.6 to 670.2 m/s and 4.30 to 12.0 m, respectively. The average velocity and thickness ranged from 559.6 to 548.0 m/s and 9.43 to 8.63m with differences of 11.6 m/s and 0.83 m respectively. The VW/VS ratios ranged from 0.955 to 1.059. This indicates that the uphole velocity is higher than the surface refraction velocity leading to low VW/VS values. This is a direct experimental proof of a low velocity zone, confirming the weathered nature of the area. The results of both refraction methods are reliable; the differences in surface refraction values are due to shot point offsets. Based on these findings, it is recommended that shots for seismic surveys should be located above 15.0 m in the area to delineate the effects associated with weathered layers to ensure that will be competent to withstand engineering structures.  

Shallow-Water Seismic Surveys ¿ How Much Noise Are We Introducing Into the Ocean?

OCEANS 2006 ◽  
2006 ◽  
Author(s):  
A. Gontz ◽  
L. Hatch ◽  
D. Wiley ◽  
E. Remillard
Keyword(s):  
Shallow Water ◽  
Seismic Surveys

scholarly journals THE SUBSURFACE STRUCTURES IN KOCR FIELD IN THE NIGER DELTA, NIGERIA, USING 3D SEISMIC TIMELAPSE DATA

2020 ◽  
Vol 5 (1) ◽  
pp. 07-12
Author(s):  
Igwenagu Chinyere L. ◽  
Uko Etim D ◽  
Tamunobereton -Ari I. ◽  
Amakiri Arobo R.C.
Keyword(s):  
Seismic Data ◽  
Niger Delta ◽  
3D Seismic ◽  
Hydrocarbon Production ◽  
Seismic Surveys ◽  
Subsurface Structures ◽  
Decline Rate ◽  
Good Repeatability ◽  
Niger Delta Basin ◽  
Monitor Data

The subsurface structures in KOCR Field, in the Coastal Swamp Niger Delta, Nigeria, are here presented, using seismic 3D timelapse. The KOCR Field lies on latitudes 4o50’58’’-4o55’19’’N and longitudes 6o18’41’’- 6o26’41’’E with aerial extent of 840km2. The base (1997) and the monitor (2009) seismic surveys resulted in a 4D response difference. The Base and Monitor data have a root-mean-square repeatability ratio (RRR) of 0.38 implying a very good repeatability when considering the acquisition, processing and environmental noises. Data processing and interpretation were carried out using Petrel software. The average thickness of the reservoir is about 69m at the depth of 3932m. Reservoir pressure decline rate of 0.062psi/day resulted in production decline rate of 1192.21bbl/day. Structural interpretation of seismic data reveals a highly-faulted field. Fault and horizon interpretation shows closures that are collapsed crestal structures. All the interpreted faults are normal synthetic and antithetic faults which are common in the Niger Delta basin. The lengths, dips and orientations of the faults and horizons, in the base and monitor stacks, are equal indicative of no faults reactivation that could have resulted from hydrocarbon production. The results of this work can be used in reservoir, field and environmental management in the area of study.

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