The Exploration Applications of Seismic DHI Analysis in the Malay Basin

Abstract

The Exploration Applications of Seismic DHI Analysis in the Malay Basin Graeme G. Phipps; Graeme G. Phipps Esso Production Malaysia Inc. Search for other works by this author on: This Site Google Scholar Thomas G. Carson Thomas G. Carson Esso Production Malaysia Inc. Search for other works by this author on: This Site Google Scholar Paper presented at the Offshore Technology Conference, Houston, Texas, May 1982. Paper Number: OTC-4257-MS https://doi.org/10.4043/4257-MS Published: May 03 1982 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Phipps, Graeme G., and Thomas G. Carson. "The Exploration Applications of Seismic DHI Analysis in the Malay Basin." Paper presented at the Offshore Technology Conference, Houston, Texas, May 1982. doi: https://doi.org/10.4043/4257-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsOffshore Technology ConferenceOTC Offshore Technology Conference Search Advanced Search AbstractOver the last 15 years or-so, improvements in reflection seismic acquisition, processing and interpretation methods have enabled the geophysicist to interpret the presence of hydrocarbons directly from seismic data. This is especially true in Tertiary classic basins.Success in predicting the presence of hydrocarbons on seismic data depends on the interpreter's ability to recognize the effects they have on seismic reflections. These characteristic changes in reflection pattern are called direct hydrocarbon indicators or "DRI's". Under idealized conditions, DRI analysis can yield valuable exploration information concerning the presence, thickness, lateral limits and type of hydrocarbons present in a structure. Information concerning the presence, extent and seriousness of drilling hazards related to shallow gas can also sometimes be obtained.EPMI geophysicists have been using DHI analysis of seismic data to assist in locating and planning exploration and delineation wells in the Malay Basin. The degree of success of DHI predictions has varied markedly. The key factors that effect success have been data quality including near surface interference problems, bed thickness versus resolution restrictions, faces conditions including the presence or absence of coals, and low gas saturation. To date, a fairly high degree of success has been obtained in predicting the presence of hydrocarbons in non-coaly environments up to depths of about 7000'. Success in mapping the lateral limits of these recognized hydrocarbon zones usually depends on bed thickness and may be complicated by the potential presence of low gas saturation below the hydrocarbon/water contacts. In thick reservoir units it is sometimes possible to locate and map gas/oil and oil/water contacts thus providing the explorations with a tool for recognizing and mapping the extent of different fluid systems in multi-reservoir fields.IntroductionOver the last 15 years or so improvements in reflection seismic acquisition, processing and interpretation methods have enabled the geophysicist to interpret the presence of hydrocarbons directly from seismic data. This represents a major advance in our ability to explore for oil and gas.Interpreting the presence of hydrocarbons on seismic data first started when geophysicists noticed that some anomalously strong reflections or "Bright Spots" on the seismic sections were associated with gas accumulations in the subsurface. It was soon recognized that several other seismic characteristics could also indicate the presence of hydrocarbons and now the more general term direct hydrocarbon indicator or "DHI" has gained acceptance.Recognizing these direct hydrocarbon indicators on the seismic sections is only the first step in present day DRI analysis. The ultimate objective is to accurately predict the geologic conditions that have caused these characteristic geophysical responses. Under idealized conditions it is sometimes possible to predict with seismic the presence, thickness, lateral limits and every type of hydrocarbon present in a reservoir.Unfortunately what appears to be a typical seismic response from a hydrocarbon accumulation is sometimes caused by something completely different and explorations who have experienced unfortunate results have had reason to label DRIs' as dry hole indicators. Separating these false DRIs from true DRIs and correctly predicting the actual geologic conditions that cause the true DHIs are some of the more difficult tasks facing geophysicists today. Keywords: fluid contact, malay basin, reservoir characterization, geophysicist, amplitude, seismic data 48, accumulation, dhis, dhi analysis, water contact Subjects: Reservoir Characterization, Seismic processing and interpretation This content is only available via PDF. 1982. Offshore Technology Conference You can access this article if you purchase or spend a download.