The Innes field, lying in Block 30/24 of the UK North Sea was discovered in 1983. After a single appraisal well had been drilled and an extended production test on the initial discovery well, estimated reserves were uncertain but low. Economic development of the field was achieved in two phases, using low cost proven technology in an innovative manner. The first phase involved the use of a floating production facility. In the second phase the economic field life was extended by the tieback and production of the Innes field as a remote subsea satellite, 14 km from the floating production facilities at the Argyll Field. The Innes field produced in this mode until cessation of production in December 1990. Material balance modelling confirms the drive mechanism as solution gas drive, supported by minimal aquifer influx, with the migration of mobile gas to form a secondary gas cap. Total recovery by the end of field life has been 5.8 MMSTB, equating to a recovery factor of approximately 30 %.

7his paper was~epared Fwprafitallm *TM I WE SPE India oil and Gas CMfer~Ce and Exhibiticm held in M Oelhi, India, 17.19 Fab~1S98. 7his paper was selected fcf preaantation by an SPE Prcgram Committee following review of inforinatiw contained in m abstract subrnifted by the author(s) Cmtents d the paper, as prasentad, have not bean revmwed by !he Scciely of Petroleum Engineers and are subjed to correction by the author(s) 7he material, as presented, doss noI necessarily reflect any psition of tk Society of Petroleum Eqinoers, Is oficars, or membsrs. Papers presented at SPE meetings are subjecl fo pbTication review by Editorial Committees of tie Society of Pefroleum Engineers. Electronic reproduction, distribution, or elwage of any part of this paper for commercial purposes without the writ!en ansent of the Society of Petroleum Engineers is prohibited. Permission to reproduca in print is restricted 10 an abstract of not more than 300 words, illustratmns may not be copied. The abstract must mntain canapicuous acknowledgment of wkre and by whom fhe pa~er was presented Write Libfarian, SPE, PO Box 83383e. Richardson. TX 7~-3~, U.SA,. fex 01-972-952-9435. AbstractThe PY-3 field, located some 18km offshore TamiI Nadu in the Cauvery Basin in southeast India, was discovered by ONGC in 1988. The field which lies in license CY-OS-90/l was awarded to the consortium in the 4th exploration licensing round offered in 1991. The appraisal of the PY-3 field has shown the structure to be complex from a subsurface perspective.The reservoir comprises moderate to low quality Cretaceus sandstones of the Nannilam Formation. The sands were deposited as debriflow deposits in a trough formed by basement highs to the east and west of the field.Laterally the reservoir exhibits significant variation in rese~oir quality. Variations in the overburden stratigraphy, result in large velocity variations and hence difficulty in modelling the depth to top structure which does not exhibit closure in time.These substiface uncertainties have been accommodated by adopting a phased development. me initial phase of development activity commenced in 1996 with first production in 1997. The development comprises subsea wells tied back to a floating production unit. A total of four wells have been used to develop the field, two of which were re-entries of existing appraisal wells.Further development of the PY-3 field, involving potential water injection or infilI drilling, will be implemented depending upon early reservoir performance.

7his paper was~epared Fwprafitallm *TM I WE SPE India oil and Gas CMfer~Ce and Exhibiticm held in M Oelhi, India, 17.19 Fab~1S98. 7his paper was selected fcf preaantation by an SPE Prcgram Committee following review of inforinatiw contained in m abstract subrnifted by the author(s) Cmtents d the paper, as prasentad, have not bean revmwed by !he Scciely of Petroleum Engineers and are subjed to correction by the author(s) 7he material, as presented, doss noI necessarily reflect any psition of tk Society of Petroleum Eqinoers, Is oficars, or membsrs. Papers presented at SPE meetings are subjecl fo pbTication review by Editorial Committees of tie Society of Pefroleum Engineers. Electronic reproduction, distribution, or elwage of any part of this paper for commercial purposes without the writ!en ansent of the Society of Petroleum Engineers is prohibited. Permission to reproduca in print is restricted 10 an abstract of not more than 300 words, illustratmns may not be copied. The abstract must mntain canapicuous acknowledgment of wkre and by whom fhe pa~er was presented Write Libfarian, SPE, PO Box 83383e. Richardson. TX 7~-3~, U.SA,. fex 01-972-952-9435. AbstractThe PY-3 field, located some 18km offshore TamiI Nadu in the Cauvery Basin in southeast India, was discovered by ONGC in 1988. The field which lies in license CY-OS-90/l was awarded to the consortium in the 4th exploration licensing round offered in 1991. The appraisal of the PY-3 field has shown the structure to be complex from a subsurface perspective.The reservoir comprises moderate to low quality Cretaceus sandstones of the Nannilam Formation. The sands were deposited as debriflow deposits in a trough formed by basement highs to the east and west of the field.Laterally the reservoir exhibits significant variation in rese~oir quality. Variations in the overburden stratigraphy, result in large velocity variations and hence difficulty in modelling the depth to top structure which does not exhibit closure in time.These substiface uncertainties have been accommodated by adopting a phased development. me initial phase of development activity commenced in 1996 with first production in 1997. The development comprises subsea wells tied back to a floating production unit. A total of four wells have been used to develop the field, two of which were re-entries of existing appraisal wells.Further development of the PY-3 field, involving potential water injection or infilI drilling, will be implemented depending upon early reservoir performance.