9 COMPUTER SOFTWARE SYSTEMS, PROGRAMS AND PACKAGES FOR USE BY OIL AND GAS PRODUCTION COMPANIES, LAND MANAGERS, DRILLERS, CRUDE OIL PURCHASERS, PETROLEUM ENGINEERS, INVESTORS, SERVICE INDUSTRIES AND SUPPLIERS COMPUTER SOFTWARE SYSTEMS, PROGRAMS AND PACKAGES FOR USE BY OIL AND GAS PRODUCTION COMPANIES, LAND MANAGERS, DRILLERS, CRUDE OIL PURCHASERS, PETROLEUM ENGINEERS, INVESTORS, SERVICE INDUSTRIES AND SUPPLIERS