Kang Ujay, Beicip-Franlab punya software/module untuk faulted and fractured Reservoir, namanya FRACA. Mungkin mereka punya kantor di Jakarta ? Minta saja mereka untuk presentasi di kantor, sekalian menimba ilmu dari mereka, tahu workflow dari FRACA, i.e geometrical modeling dan modul2 simulasi yang bisa dikombinasi, dan mungkin bisa sekalian dapet referensi tentang fracture di basement.
wass. Bambang Istadi Exploration Production Technology Integrated Interpretation Center Conoco Inc. -----Original Message----- From: Rovicky Dwi Putrohari [mailto:[EMAIL PROTECTED]] Sent: Monday, July 22, 2002 7:47 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: [iagi-net-l] Masih tentang fracture di basement Ini ada tulisan dari Geoscience Ltd Webpage : masih baru looh : Last main update 11th February 2002. Compiled by Tony Batchelor, Jon Gutmanis and Colleagues of GeoScience Limited Yang menarik adalah ... penemuan ini kebanyakan --> karena "kecelakaan" (by ACCIDENT). Kalo aku kasih tau bahwa aku punya pdf filenya pasti banyak yang mau deh .... :-) rdp =============================== HYDROCARBON PRODUCTION FROM FRACTURED BASEMENT FORMATIONS INTRODUCTION This compilation presents brief details of the occurrences of commercial hydrocarbon reservoirs in fractured basement rocks from approximately 30 different countries. By definition (see below), the review concentrates only on those reservoirs found in igneous, metamorphic and volcanic rocks. The document has been assembled primarily from published literature and is therefore, to a large degree, a historical review. However, we have also incorporated responses to the sci.geo.petroleum newsgroup and endeavoured to make new information available on a regular basis. It is made available for personal interest and education only and should not be republished or distributed in any way. Data has not been cross-checked in detail against multiple references so use with care. In addition, some of the information, for example on production, will be out of date since it is based on historical sources. Information updates, corrections and comments are welcome. Has your Company found an example that we can use in the public domain to validate these occurrences? We would appreciate the data, please help support Version 8. We know from our own work that there are several fields in various countries that are not included here because no information has been released in the public domain. We will make it available as it is released. ----- Last main update 11th February 2002. Compiled by Tony Batchelor, Jon Gutmanis and Colleagues of GeoScience Limited. BACKGROUND A large proportion of the world's proven oil reserves have been found in reservoir rocks that are naturally fractured (Waldren & Corrigan, 1985; Nelson, 1985; Aguilera, 1995; Nelson, 2001). In his updated book, Nelson (2001) gives a list of some 370 fields where natural fractures are important for production and a significant proportion are in basement settings. Nelson (2001) also states that "...in BP Amoco alone, current and future fields in various types of fractured reservoirs are estimated to account for some 21 billion barrels of oil equivalent (BBOE)". The occurrence of naturally fractured basement reservoirs has been known within the hydrocarbon industry for many years but generally regarded as non-productive, they have failed to draw the attention of the explorationist. Often passed over as 'of no economic potential', their investigation by exploratory drilling has been left to chance. Yet, they are commonly distributed in various petroliferous regions throughout the world. As early as 1948, Eggleston (1948) carried out a comprehensive survey of oil production from fractured basement rocks in California and found that 15,000 barrels per day were being produced from such rocks. This represented about 1.5% (918,000 barrels per day) of the total California production at that time. Hubbert and Willis (1995) produced a comprehensive list of fractured reservoirs in the United States. According to Landes et al (1960), about 100 million barrels of oil had been produced by that time from various basement rock sources worldwide with initial productions being as high as 17,000 barrels per day. He goes on to suggest that with accumulation of oil in such quantity, from a source often as not found by accident, the probable reserve in fractured basement rocks is of such a magnitude that discovery by design should become the rule. Reservoirs in fractured basements, where the oil and gas in place may be held within an extensive fracture network on a variety of different scales rather than within the matrix porosity of the formation, present challenging problems to the petrophysicist and reservoir engineer. Fractured reservoirs are much more difficult and expensive to evaluate than the more conventional reservoirs (Nelson, 1982, 1985, 2001). A greater understanding of the fracture distribution and connectivity within basement reservoirs may prove to be the key tool for improved exploration and production management of this hidden resource. Commercial, naturally fractured basement oil deposits have been found largely by accident, whilst looking for other types of reservoir (Aguilera, 1980; Landes et al, 1960). Landes et al, (1960) postulated that basement rock oil accumulations are not freaks to be found solely by chance but are normal concentrations of hydrocarbons obeying the rules of origin, migration and entrapment. Therefore, in areas of not too deep basement, oil deposits should be sought with the same professional skill and zeal as accumulations in the overlying sediments. Landes (1959) stated that once the basement rock had been reached during drilling, it was thought that there was little or no chance for oil production. Many oil companies still stop drilling operations as soon as basement rocks are intersected. Aguilera (1995a) suggests that drilling should be continued into the basement rocks for at least 300 m, especially if the basement is overlain by an oil yielding formation. Kenney (1996) states that in the western countries, all of the oil fields that produce from crystalline basements were discovered by accident. Aguilera (1995b) and Russell (1995) continue, stating that most naturally fractured reservoirs (sandstones, carbonates, cherts, shales and not just basement reservoirs) were discovered by accident. In Russia and some of the other countries of the Former Soviet Union (FSU) however, drilling into crystalline basements has been carried out intentionally (Kenney, 1996), although a literature search reveals that citations of producing fields in basement are actually few and far between. Landes (1959) wonders how many oil discoveries have been missed because of inadequate exploration of the barely scratched basement by unsuccessful wildcats. ==== seterusnya ada di paper yang yang 600 KB. --- mau ? Example from Indonesia Sumatra - Beruk Northeast The Beruk Northeast oil field of Central Sumatra was discovered in 1976 with the drilling of the Beruk Northeast Well No. 1 into a Pre-Tertiary basement. The oil field is located within the Central Sumatra BackArc Basin, one of a series of Tertiary basins oriented along the western and southern margin of the Sudan Craton. In addition to Beruk Northeast, only four other fields have been reported as producing from Pre-Tertiary basement in Indonesia. Koning & Darmono (1984) state that oil production from Pre-Tertiary rocks is exceptional in Southeast Asia. The Beruk Northeast field is situated within a group of oil fields in the central area of the Pertamina-Calasiatic-Topoco Coastal Plains-Pekanaru Production Sharing Block. The basement rocks, which tested oil, consist of fractured metaquartzites, weathered argillites and weathered granite. Beruk Northeast Well No. 1 was drilled to a total depth of 1,634 ft into the basement. An openhole test of the basement flowed at 1,680 bbl/day. A thin Telisa sand located approximately 100 ft above the basement was tested and flowed at 480 bbl/day. By 1984, Beruk Northeast Well No. 1 had produced in excess of 1,100,000 barrels of oil, 640,000 barrels of water and 42 MMCF of associated gas. All production from the well has been obtained through the naturally occurring fracture system in the Pre-Tertiary basement metaquartzites (negligible matrix porosity exists from core studies). Subsequent development wells have been less productive, possibly due to the poor characteristics of the weathered argillite and granite reservoirs (Koning & Darmono, 1984). In the Sei Teras field, South Sumatra, 15,000 barrels of oil and 1 BCF of gas has been produced since 1977 from two wells in basement limestone and quartzite. Approximately 21 million barrels of oil and 14 BCF of gas has been produced from Pre-Tertiary rocks in the Tanjung field, South Kalimantan (Koning & Darmono, 1984, after Tiwar & Taruno, 1979). The basement rocks in this field consist of porphyritic extrusives (lava) and volcanics as well as metamorphosed sandstones, shales and claystones. In both the Sei Teras and Tanjung fields, the basement is locally deeply weathered and fractured (Koning & Darmono, 1984). Java - Jatibarang Field The Jatibarang field is located in Northwest Java, approximately 200 km to the east of Jakarta. The field produces from eight shallow sedimentary zones, but major production zones are in naturally fractured volcanic formations (Soewono & Setyoko, 1987). The Jatibarang volcanic formation consists of lava flows (andesite/basalt), tuff and agglomerate/ volcanic breccia. Oil was first discovered in the volcanic reservoir in November 1969 with the drilling of Well JTB-44, at a depth of 2,011 m (Sembodo,1973) and has been developed since 1973. Initial production from 20 wells was approximately 40,000 bbls/day. Since then, many wells have been drilled, the production of which varies from 250 bbls/day to 3,000 bbls/day. The depth of wells varied between 2,000 m and 2,300 m, with hydrocarbons found between 1,900 m and 2,200 m (Sembodo, 1973). By April 1987, the cumulative recovery of the Jatibarang volcanic reservoir was 83.9 M bbls of net oil from 136 wells (Soewono & Setyoko, 1987). Kalan et al (1994) present the results of a geological investigation of the Jatibarang Field performed in 1991/1992 by Elf Aquitaine Indonesia. The investigation was part of a feasibility study into the utilisation of horizontal drilling to improve production from the Jatibarang volcanics. The feasibility study concluded that the drilling of horizontal wells would provide increased recovery from the volcanic reservoir (actual production figures were not provided). Fracturing in the volcanics is believed to be the most intensive in the tight folds of the Central and Western Blocks which accounts for the good production (previously discussed above). Kalan et al (1994) proposed the use of a horizontal well in the Eastern Block of the Jatibarang Field where the volcanic reservoir has produced less than expected due to lower intensity of folding and fracturing. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] ===================================================================== pesan sponsor: visit http://iagi.or.id sukseskan PIT IAGI di Surabaya, September 2002 --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] ===================================================================== pesan sponsor: visit http://iagi.or.id sukseskan PIT IAGI di Surabaya, September 2002
