Modern Seismic Methods - An Aid for the Petroleum Engineer

Abstract

This paper describes the emerging detailed seismic techniques that often can provide considerable help for the petroleum engineer. Five areas of mutual interest for the geophysicist and petroleum engineer are identified. Primary emphasis is on the use of seismic data for reservoir identification. Introduction Today, petroleum engineers are faced with unprecedented challenges in every phase of their profession. Increasing costs, more difficult development targets, and exotic recovery techniques make it imperative that the engineer be aware of all available technology for meeting these challenges. Of particular interest are new seismic acquisition, processing, and interpretative techniques that have improved significantly in the last 5 years and now represent an important new exploitation tool. The engineer should be aware of these improved capabilities and should be prepared to use appropriate seismic entry data to help solve his problems. Summary Areas of mutual interest for the petroleum engineer and the geophysicist can be summarized as follows. Exploration/Production Interface Preparation and Evaluation of Analogs. Petroleum Preparation and Evaluation of Analogs. Petroleum engineers are involved in evaluating existing fields, producing trends, or provinces. The engineer directly producing trends, or provinces. The engineer directly influences exploration efforts by his assessment of the economics of established production, and indirectly influences exploration activities by his evaluation of rock and fluid properties, which are, in turn, used in seismic interpretation. Development of Velocity and Density Depth Trends From Wellbore Data. Similar to the preparation of analogs, engineers often develop formation parameter trends from which various combinations of earth acoustic properties can be tested. Since the quality of these trends properties can be tested. Since the quality of these trends often depends on the way wells have been drilled, engineers should have some degree of control over data acquisition. Forecasting. Engineers may influence exploration activities by their forecasts of required drilling/production capital, operating costs, and product prices. However, a forecast of exploration activities influences such engineering predictions as drilling rig and tubular requirements, and production schedules for a trend, province, division, or company. Bid Preparation and Property Purchases. In most companies, engineers and exploration personnel work together in preparing acreage bids and evaluating property purchases. The engineer must understand the property purchases. The engineer must understand the applications and limitations of seismic data, a principal exploration tool. Field Development Extent of Hydrocarbon Accumulation From Lateral and Vertical Limits. Lateral limits include salt face, porosity pinchouts, and faults; vertical limits include porosity pinchouts, and faults; vertical limits include fluid contacts and porosity pinchouts. JPT P. 1519

Shear Wave Velocities Determined From Long- and Short-Spaced Borehole Acoustic Devices

“…When comparing P-and S-wave ITT curves recorded in the field with those produced from waveform time picks, no systematic difference is noted and agreement is generally excellent. OCTOBER 1980 Comparing waveform time-picked ITT curves for both P-and S-waves and for multiple tool spacings shows that long spacings generally have slightly lower ITT than short spacings, with the spacing curves generally being in sequence (i.e., lower ITT as spacing increases). The long-and short-spaced curve offset is present in all lithologies.…”

“…Copyright 1980 Society of Petroleum Engineers OCTOBER 1980 designed primarily for detection of P waves. Downhole amplifiers adjusted to accentuate the first P-wave arrival normally saturate through the shear and late P regions of the waveform.…”