Environmental / Engineering Dinner Meeting

"Environmental pilot testing technologies and methodologies "

Author: by Jim Sadler, AcuVac Remediation, Inc.

Date: Wednesday, December 8, 1999

Place: Jalapenos - 2702 Kirby (at Westheimer)

Time: Dinner 6:30 PM, Presentation 7:30 - 8:45

Cost: Click here

Reservations: Make or cancel reservations by Dec 6. You MUST include a name and a contact telephone number for every person for whom you are reserving or canceling a place. HGS members are requested to provide their HGS member number. Note: Some people have experienced a problem with this email reservation system. If you do not receive a confirmation from the HGS office, please call the HGS office (713) 785-6402 to verify your email reservation was received.

The presentation will consist of a technical discussion of environmental pilot/feasibility tests. Various technologies and methodologies, such as Soil Vapor Extraction (SVE), Enhanced Vacuum Recovery (EVR), also referred to as Vapor Extraction-Groundwater Extraction (VEGE), Dual-Phase Vacuum Extraction (DPVE), Air Sparging (AS), and SVE Quick Tests (QTs) will be presented. The results of a recent pilot test will be discussed to point out the many variables and outside forces that can affect precision testing.

Biographical Sketch:

Since 1957 Jim Sadler has been associated with oil refining, marketing and environmental remediation following his graduation from the University of Texas with a degree in mechanical engineering. After his first job with Ethyl Corporation as an automotive engineer, he was employed by Tenneco in the Refining and Marketing department, where he was directly involved in developing the "convenience store with gasoline" concept and became VP of marketing.

He later decided to start his own marketing company, primarily involved with developing the concept of self-service gasoline. In eight years, Autotronic Systems Inc. was built to 750 self-service stations in 23 states. After the company was sold to Sigmor, he became a consultant for Coral Petroleum to develop its marketing in upstate New York and Pennsylvania. This was his introduction to environmental problems associated with USTs.

In 1991, Jim's wife Leiselle Mathews started a marketing company for the S.A.V.E.(trademark) remediation system. Jim and Leiselle recognized a developing trend and demand for pilot testing, and the company rapidly became a service company. The company developed the methodology for the reporting of accurate and useful data for CAP plans. Since 1991, AcuVac Remediation, Inc. has conducted over 1,500 pilot tests. Mr. Sadler has over 10,000 hours of on-site testing.

International Dinner Meeting

Timor Sea (Australia/Indonesia) Discoveries, 1994-1998

Authors: Frank Maio and Steve Plybon, Maio-Plybon Geoscience, Dallas, Texas

Date: Monday, December 13, 1999

Place: Westchase Hilton, 9999 Westheimer

Time: 5:30 pm Social 6:30 pm Dinner

Cost: Click here

Reservations: Make or cancel reservations by Dec 10. You MUST include a name and a contact telephone number for every person for whom you are reserving or canceling a place. HGS members are requested to provide their HGS member number. Note: Some people have experienced a problem with this email reservation system. If you do not receive a confirmation from the HGS office, please call the HGS office (713) 785-6402 to verify your email reservation was received.

Talk Abstract:

INTRODUCTION

The Timor Sea (Australia/Indonesia) has had a remarkable string of successes beginning with the discovery of oil in Elang field in early 1994. Oil discoveries in an area that was previously thought to be mainly gas prone have captured the interest of the industry, and new geological concepts and better seismic technology have lowered exploration risks. New significant gas pools are also being found or actually re-found in the case of one discovery. Gas development plans will rely on the synthesis of various LNG projects and the improvement of South East Asian economies.

SYNOPSIS of REGIONAL TECTONICS

The discoveries examined in this paper are situated within the northeastern Browse Basin and in the Bonaparte Basin. (See Figure One) In this region, Late Jurassic rifting formed a horst/graben topography in the basin centers and tilted terraces on basin margins. The Kimmeridgian through early Valanginian rift sequence is represented by alluvial to submarine fans shed locally off intermittantly active basin margin faults and by restricted marine shales of good source rock quality in the basin centers. The last crustal extension of the Mesozoic produced the mid-Valanginian unconformity that represents the final separation of Australia and India. Post rift thermal sag marine shale deposition then predominated until a Mid Cretaceous regional lowstand produced erosion on the margin of the Londonderry High and subsequent deposition of clastics. The early Tertiary was mainly tectonically quiescent, with passive margin carbonate marine shelf sedimentation predominant; however, inversion events have been recognized locally in various parts of the basin. Oblique collision of the northern Australian margin and the Indonesian plate began in some areas in the mid-Oligocene, and culminated in regional major reactivation of older faults in the late Miocene. This collision resulted in the beaching of numerous oil and gas pools in the Timor Sea and re-migration of hydrocarbons. Rejuvenation along faults occurs at present; for example, pre-drill presence of hydrocarbons in the Cornea area was indicated by a seismic amplitude anomaly, by radar imaged oil slicks and by positive results of a water bottom "sniffer" survey.

RESERVOIRS

With the exception of Cornea field all the pools discussed in this paper include some part of the Bajocian to mid-Callovian Plover Formation and/or the mid-Callovian through early Oxfordian Elang Formation. These reservoirs are interpreted to have been deposited in an overall transgressive setting ranging from fluvial channels to tidally influenced estuarine shoreline sediments to upper shoreface units. Cornea field reservoirs are Early Cretaceous alluvial to fluvial sands deposited on the southern margin of the study area.

STRUCTURAL STYLE

The majority of the Jurassic accumulations are pooled in three-way closures against faults. Laminaria and Bayu/Undan fields are exceptions in that they are large regional highs with four-way closure. Cornea field consists of a four way closure created by drape over a basement high. 3D seismic has been helpful in confirming fault presence and extent. Seismic resolution of the surface of Jurassic objectives is often difficult and interpretation must include identifying truncations at unconformity surfaces.

TIMOR SEA FIELDS

• ELANG/KAKATUA

  The Petroz Elang 1 was the discovery that proved the presence of economic oil fields in the eastern Timor Sea. The prospect was originally mapped in the early 1970's but drilling was delayed due to the boundary dispute between Australia and Portugal known as the "Timor Gap". The field trap is formed by three way closure against a series of faults. Seal is provided by juxtaposition of lower Cretaceous shales against Jurassic Callovian-Bathonian Elang sands. Elang 1 was completed in early 1994 and had a maximum flow of 5800 BOPD, GOR of 550 scf/stb. The well intersected a gross oil column of 76.5m, and the sands have core measured permeability up to 2.2 Darcies and porosity up to 17 percent. Elang 2 successfully tested the western field extent. Nearby, Kakatua 1 and Kakatua North 1 tested similar but smaller features. All three fields were developed using an FPSO (floating production storage and off-loading) facility and subsea completions. First production of 33,000 BOPD began in mid 1998, and recoverable reserves are estimated at 29 MMBbls.

• LAMINARIA/CORALLINA

  The Laminaria feature was mapped in the early 1970's but drilling was also delayed due to the "Timor Gap" boundary dispute. Laminaria 1, drilled in August of 1994, tested a regional high consisting of several E-W and ENE-WSW trending tilted horst blocks. The objective horizon is weakly identifiable on seismic due to low reflectivity, but overlying shale sequences are more easily interpreted. Truncations at the unconformable surface of the top reservoir aid in the mapping process.

  The well intersected a 109m gross oil column in Callovian-Oxfordian sands and tested at a maximum flow rate of 7,507 BOPD 590 API oil with a GOR of 175 scf/stb. The nearby Corallina feature has also been tested positively for oil. Recoverable reserves are estimated to be over 200MMBbls, and will begin to flow in late 1999 from a development scheme that involves seven subsea completions and an FPSO situated in 390m of water.

• BAYU/UNDAN

  Bayu 1 was completed by Phillips ZOC and the ZOC 91-13 permit partners on 3 March, 1995. A 155m hydrocarbon column was encountered in Middle Jurassic sandstones from which a cumulative flow rate of 90 MMcfg/d and 5,250 bc/d was achieved from four test intervals. Nine subsequent appraisal wells drilled on ZOC 91-13 and on adjacent permit ZOC 91-12 have outlined a 34 km long by 16 km wide (21 miles by 10 miles) supergiant gas/condensate accumulation. Estimated recoverable reserves are 3.4 Tcf and 400 MMBbls liquids. A liquid stripping, gas reinjection development plan has been approved by the joint venture and will be operated by Phillips Petroleum. First liquid production of 110,000 b/d is estimated to begin by 2003. The field lies entirely within the Zone of Cooperation and is located 500km north-northwest of Darwin, Northern Territory.

• EVANS SHOAL 2

  This well, operated by Shell, drilled a typical Timor Sea tilted fault block with three way closure. It tested up to 25.5 MMcfg/d, with 3.8 bbls cond/mcf from Mid Jurassic Plover sands. The gas is mainly methane, and also contains 26% CO2. Recoverable reserves are estimated to be in the 5.6-10.5 Tcf range.

  The significance of this test is that is was drilled updip from a 10 year old well on a permit awarded to a small Australian independent who successfully farmed in Shell. The operator of Evans Shoal 1 acknowledged a significant gas resource, but at the time gas was not in favor and so the operator relinquished the permit. This field fits well into Shell's long term vision for LNG development in the region as Shell (and Woodside) also have significant gas reserves to the north (Sunrise-Troubador).

• CORNEA/SPARKLE

  The Shell Cornea 1 well was drilled in late 1996 under high security conditions because at the time the adjacent permits were on offer to the industry. A few kilometers updip from an early 1970's dry hole, it tested a four way closure formed by the draping of Cretaceous sediments over a Pre-Cambrian basement high. A subsequent well (Sparkle 1) found an oil and gas pool in Cretaceous sands pinched out against basement. The significance of these fields lies in the fact that they proved long distance migration of hydrocarbons (at least 60 kilometers) from the nearest source kitchen to the traps. The industry is now engaged in regional search for similar plays along the entire margin of the northern Australian shelf.

  Although none of the wells have been extensively production tested, initial results indicated the potential of 2 billion+ barrels of oil in place at drilling depths under 1000m and in water depths of under 100m. Thus after drilling Cornea 1 the Shell/Chevron/Cultus venture made an astounding bid of 44 wells plus several thousand of kilometers of seismic on the adjacent two permits. (Needless to say, they were awarded the permits.) Subsequent drilling drastically reduced the original oil in place estimation, and the partnership has been allowed by the Australian government to relinquish the permits without fully living up to their well and seismic commitments. It remains to be seen what the consequences will be for the offending companies of this breach in contract terms. The permits will probably be recycled and offered to the industry again within a few years.

Biographical Sketch

Frank Maio is a Director of Maio-Plybon Geoscience (MPG) in Dallas, Texas. Previously he worked 18 years for Oryx Energy in a variety of exploration and production roles in domestic and international basins. He has a BS in Geology and a BBA in Management, and is a member of the following organizations: Dallas Geological Society, Houston Geological Society, AAPG (certified), and Petroleum Exploration Association of Australia.

Steve Plybon, a Director of Maio-Plybon Geoscience (MPG) in Dallas, Texas, has spent over 20 years as a petroleum geophysicist in a variety of international and domestic US technical positions. Most recently, Steve worked on 3D projects in the Texas Gulf Coast region. He has a BA in Math and an MS in Geophysics and is a member of the American Association of Petroleum Geologists, the Society of Petroleum Geophysicists, and the Dallas Geophysical Society.

MPG offers consulting services that include basin analysis, exploration and production asset evaluation, farmout promotion and software marketing. For further information please see http://home.earthlink.net/~mpgeo.

Poster Number One:

3D SEISMIC INTERPRETATION AND NON-MARINE DEPOSITIONAL PROCESSES AT THE GORGON GAS FIELD, NW SHELF, AUSTRALIA*

By BARBARA J. RADOVICH, Texaco Exploration, 4800 Fournace Place, Bellaire, Texas 77401-2324 and BURNET OLIVEROS

ABSTRACT

As part of the ongoing assessment of the Gorgon gas field on the NW Shelf of Australia, Texaco conducted a detailed sequence stratigraphic study of the 3D seismic data and well ties in the gas-bearing sands of the Triassic, non-marine Mungaroo section. This gas field is on a series of tilted horst blocks in the northern Carnarvon Basin and is being appraised by a partnership of Texaco, Shell, Chevron, and Mobil. The data reveal a non-marine sequence stratigraphic framework dominated by the processes of incision and aggradation. Understanding these processes allows the sequence stratigrapher and quantitative geophysicist to produce a more geologically insightful interpretation and calibration of the 3D seismic geometries and amplitudes.

The analysis of the wireline log shapes shows the pays sands are a series of stacked, high energy fluvial sands. They are characterized by blocky gamma ray shapes with sharp bases followed by fining-upwards patterns. The 'base' of each sand is a sequence boundary and log correlation indicates incision into older units at this boundary. Each fluvial event is capped by low energy siltstones and mudstones. The porous sands are low impedance compared to the siltstones and mudstones.

The 3D seismic data show that incision at each sequence boundary is a major part of the interpretation of the seismic data. The sequence boundary is the time-correlatable horizon on the workstation and allows proper delineation of each pay sand amplitude . Interpreting tops of sands in this setting is not recommended as the top is usually a time-transgressive horizon.

The 3D seismic amplitude extractions on each fluvial event reveal high amplitude lineaments and low amplitude areas. These amplitude maps represent, to some degree of resolution, the original stratigraphically-controlled, plan-view pattern of sandy lithofacies. The sand-prone facies develop along fluvial depositional axes and are interpreted along the high amplitude lineaments. The mud-prone interfluve lithologies are interpreted in the low seismic amplitude areas. The instantaneous frequency of the seismic data can be used to correct for changes in seismic amplitude due to changes in thickness of the sand around the tuning frequency. 'Sweet spots' on the maps can then be more accurately represented. But the amplitude patterns displayed on the maps have also been altered in places by the constructive and destructive interference effect on the seismic amplitudes that results from the sands getting too close from above or below. These interference zones are caused by the process of incision at the parasequence boundary for each fluvial event. Corrections should also be made to reduce the interference effects before seismic amplitudes are used in a quantitative way to build reservoir models.

*This poster material was published in the GCSSEPM Foundation 17th Annual Research Conference 1996.

Poster Number Two:

Structural history of the Northwest Shelf, Australia: an Integrated Geological, Geophysical, and Experimental Approach by Gloria Eisenstadt and Martha Withjack, Mobil Technology Company, Dallas, TX