b'Seismic window Seismic windowa terminal on most desks so we couldproduce detailed velocity profiles that plot posted maps for hand contouring.conform to geological features. There are The Delhi mapping software was at thelimitations such as the restricted depth of forefront of technology and I recall ainvestigation and cost although the latter team from Esso travelling from Sydneyis being reduced as computing power to check it out. becomes cheaper and faster. Another Of course, support staff werevelocity related issue is anisotropy or abundant. We had technical assistants,variations in velocity dependent on draftspersons, surveyors and secretariesthe direction of travel. The inclusion of so we could spend our time lookinganisotropy parameters in the velocity at seismic data rather than makingmodel improves well ties and extends power points, which werent inventedthe number of useful traces at far yet, typing memos or digitising. Theoffsets which possibly results in a better company bought the first fax machine instack and constrains AVO inversion Michael MicenkoAdelaide, but had to wait for someonepossibilities.Associate Editor for Petroleumelse to buy one before they could use it.So, there you have itthere have been micenko@bigpond.com Actually, it was mainly used to receivehuge changes in the industry since I logs from the well site. Prior to this westarted but I think the most important would charter a jet to fly to Moomba,change is the ability to create detailed 40 years of change pick up the logs and return them toand accurate velocity models.Adelaide the next day. Today we get real time logs displayed on our desk top My favourite geophysicist retired earlierwhile drilling.this yearthats right, Interpreter Sam will no longer be gracing the back page of The Leading Edge. This got me thinking about the last 40 years since I started in the oil industry with Delhi Petroleum in Adelaide. After spending the late 70s taking field measurements for minerals companies and the SA Department of Mines my first experience with Delhi was a real eye opener - I received a 20% pay increase between the job interview and my first day. The job interview consisted of a morning answering questions in a psych test and then being taken to lunch by the exploration team. If youThats enough reminiscing so lets survived the afternoon you got the job.move on to asking what has been There was not an HR person in sight andthe most significant improvement the Exploration Manager never looked atover the last 40 years. I could say 3D the nut test results. seismic and everyone would probably So, what else has changed since 1980?agree but I will stick my neck out Seismic data was supplied as paperand go with velocity modelling. An sections and interpreted with colouraccurate velocity model is crucial pencils. Derwent were preferred overto obtaining a good image of the Staedler by most of my colleagues.subsurface. It does no one any good The exploration group had a singleto have a 3D volume of multiples and Tektronix computer (total RAM 8 Kbyte)noise. Processing companies spend a that was used to digitise interpretedhuge effort to obtain the best velocity horizons and sonic logs, the latter beingmodel possible because an accurate used as input to calculate syntheticvelocity model results in good time to seismograms which took several hours.depth conversion, multiple removal, Delhi was one of the few companies inflat gathers and the best possible migration. Name the logo quiz - a bottle of red to the first Australia that could create these usefulperson to correctly name the companies that used overlays. Being a progressive company,Full Waveform Inversion (FWI) hasthese logos. Hint: they were active at least 25 years we soon had a VAX/VMS computer andbecome a mainstream process and canago. Reply to my email above.41 PREVIEW APRIL 2020'