RESERVOIR GEOLOGY AND PRODUCTION PERFORMANCE OF...

MEETINGS HGS D I N N E R MEETING- NOVEMBER 9,1992 Social Period, 5:30 p.m. Dinner and Meeting, 6:30 p.m. P o s t Oak Doubletree Inn

ERIK P. MASON-B iograph ica l Ske t ch

Erik isasenior Geolo- - gist i n the Shelf Division at shell Offshore Inc.. New Orleans. H e received his Bachelor's and Master's degrees in geology from Pr inc ip ia Col lege and Oklahoma State Univers- ity. respectively. He joined 1, , .I Shrll in 19RRaiter spending 5 years will1 Phillips Pet- roleum, where he worked

. , in both domestic develop^ ment (Gulf Coast) and international erp lorat~on (Indo-Pakistan) geology.

,'it S l i ~ ~ l : it,, ;I.:. !~, i i i i r .d o n fully integrated fi(,lcl studies at Suutli l i n i i d c r 295and Eugene Island 188 fields, primary development o f Eugene lslancl30 Field. arid surveillance of several smaller fields. He has authored and coaulhored several in-house reports and publications.

Erik is an active member of AAPG. NOGS, and the Computer Orientetl Geologic Society. He has been a member o f HGS since 1933 and was chairman of the Continuing Education Committee from 1986-1987.

RESERVOIR G E O L O G Y A N D P R O D U C T I O N PERFORMANCE OF T U R B l D l T E S A N D S A T

S O U T H T l M B A L l E R 295 FIELD, OFFSHORE LOUIS IANA:

S O M E E N C O U R A G I N G RESULTS

Uncertainty exists concerning the range of production performances to expecl from diflerent deep water reservoir f c l i t ~ s . South Timbalier 295 is one of a select iew Gulf of Mrxtco fields with production history data available from several different turhidite depositional settings.

oil and 125 hillinn cubic feet of gas. Avery si~ccesslul six.well drillingprogram was recentlyconducted and was hased on a fr~lly i n t ~ g r . > t ~ d (3-D seismic, well and prodl~ct ion data) firld study compleled in 1991. Cross sections and detailed field maps were constructed lor every pay sand. Additionally, a sertcs of subregional intcrval and twt sand isopachs were h i l t and then used toreconstruct the tectonic history of the area. which helped definr how paleostructure influenced deposition.

The "KR." intrrpreted as a series of rntd-fan turhidite sheet sands which lapped ontoa palenhigh, ischaracterizrd by g o d lateralcontinuity. Over 1.200.000 harrrls of oil have hrm ~ i rod~ rced from Well A - I 2 at a suslained daily rate o f 1,400 harrels with only a small pressure change. The initial rati. iron1 Well A-22, recently rnmplefctl, i s 1.500 harrels

daily. Both wells appear to be in pressure communication. Hydrodynamic pressure is likely.

The "Klb" consists o f amalgamated channel sands characterized by rapid lateral variation. Interval and net sand isopachs also indicate thinning onto a paleohigli. Despite the channelized architecture of the "K16." connrc- tivity of channels across amalgamation surfaces appears to he common. Sustatned daily production rates ranging from 1,000 to2.000 barrclsof oil from three separatecornpletims with little pressure c h a n g ~ indicate connection to a large aquifer.

The "K40" consists of two separate turbidite ponded basin sheet sands which onlapped a paleohigh and pinchout updip. Nearly 1.200.000 barrels of oil have been produced from wells A-5. ,425, and A-27 at sustained races of 1.200. 2,000 and 3.100 harrels of oi l daily. Good recovrrics. litti<, pressure change. .and noticeable movemenc of the nilbvater contact suggest excellent continuity and support by a large downdip aqu~ler.

All three reservoirs are fine-grattied, moderately well sorted subarkosic sandstones. Porns~ty and prrmeahiltt y are approximately 31"'. and 500 md. rcspcctivclv. for 311 three reservoirs.