The average porosity of fractured reservoir is small, about 23% while the permeability is distributed in relatively wide range. Fractured basement reservoir ilmiah july 12, 2010 posted by ibnu dwi bandono in geology time. Fractured basement reservoirs characterization in central. As production from the ukcs continues to decline, and with the exploration potential of more traditional plays becoming increasingly.
Oil discovered in fractured basement of bach ho oil field on may 1986 in cuu long basin, vietnam start producingstart producing from bfrom basement. Therefore, fracture identification and characterization is of the upmost. Fractured basement reservoirs in central sumatera basin would be a future indonesian oil and gas development. Type 1 tectonic fractured reservoir, ain zalah field aqrawi et al. Natural fracture propping and earthquakeinduced oil. Fractured basement reservoirs are naturally fractured and do not require additional fraccing. Because of his expertise in formation evaluation analysis using welldata, currently he is a vice president of formation evaluation society of malaysia fesm. A case study from the west of shetland finding petroleum. Fractured basement reservoirs require a specific approach when acquiring and interpreting. Therefore, the approach to modelling fractured basement reservoirs cannot necessarily be repeated between different fields and a more bespoke approach is required that is sensitive to the particular characteristics observed. A multidisciplined team ethic, carefully integrating these data while avoiding a siloed approach, has proved essential to understanding the behaviour of the connected fracture network. Pdf characterization of a fractured basement reservoir. Case studies of fractured basement reservoirs hydrocarbons.
Water coning in fractured basement reservoirs onepetro. The workshop will emphasizes of petrophysical evaluation and fractured. Overview oil discovered in fractured basement of bach ho oil field on may 1986 in cuu long basin, vietnam start producingstart producing from bfrom basement. The occurrence of naturally fractured basement reservoirs has been known within the hydrocarbon industry. Fracture frequency is variable, up to 2040 per metre of core. These difficulties are attributable to the heterogeneity of the reservoir formation, which causes substantial uncertainties in estimates of oilgasinplace ogip and in reserves estimates res.
Revitalize reservoirs for less than the cost of plugging and abandoning, paid for by increased production. South sumatra produced at least 8 factors activators of fracture generation, with an order of. An analog outcrop model needs to be conducted as a first step toward predicting subsurface fracture system attributes. Characterisation and modelling of fractured basement. Oil has been produced from fractured basement reservoirs for decades. Fractured granite reservoirs the buried hill basement play in the cuu long basin is unusual in the fact that the shale source rocks are younger than the fractured reservoir.
Role of tectonics in development of fractured basement reservoir in mumbai high field, western offshore basin, india k. Lancaster development making fractured basement reserves viable november 2017 establishing, predicting and modelling the hydrodynamic fracture network of basement reservoirs during the exploration and early appraisal phase. Characterization of fractured basement reservoir using statistical and fractal methods 593 korean j. View enhanced pdf access article on wiley online library html view download pdf for offline viewing. The problem of water coning in fractured basement reservoirs has been addressed in this work. Pdf well trajectory impact on hydrocarbon discovery in. Pdf on jan 1, 2009, jon gutmanis and others published basement reservoirs. The purposes of this association are to advance the science of geology. Naturally fractured basement reservoirs aapg datapages. Basement reservoirs are a subset of naturally fractured reservoirs and the term basement refers to crystalline formations ranging from intrusive and extrusive magmatic bodies especially granites to the family of low to mediumgrade metamorphic rocks 19. A discrete fracture network dfn model is made to represent two fracture set explicitly, based on spatial and nonspatial parameters.
The main payzone in this field is in the basement, which is composed of granites and granodiorites. A casestudy of fractured basement reservoirs in damintun depression of liaohe basin. Characterisation of fractured basement reservoirs, cuu long. In comparison, basement argillites tend to be ductile and do not fracture readily and typically are not good basement reservoirs. The numerous examples of successful fractured basement developments demonstrate that a variety of. To date, fractured crystalline basement reservoirs basement on the uk continental shelf ukcs have largely been underexplored, despite the fact that numerous indications of hydrocarbons have been reported from basement in wells dating back to the 1970s. The lancaster fractured basement is classified as a type 1 naturally fractured reservoir nfr, as it contains little to no intergranular matrix porosity or permeability and, as such, the reservoir behaviour is entirely dominated by the fracture network nelson 2001. Clair 206816, clair group devonian, calcite fracture fill cutting sandstone, depth 1879. First oil from the fractured basement in hurricanes lancaster field, located along the prominent rona ridge basement that is home to most of its portfolio, can now proceed this year after the aoka mizu floating, production, storage and offloading vessel successfully connected to the early production system on 19 march.
Fractured basement reservoirs require a specific approach when acquiring and interpreting formation and well test data. The american association of petroleum geologists is an international organization with over 38,000 members in 100plus countries. Emplacement and biodegradation of oil in fractured. Transpressional wrench faulting in the late oligocene in this part of the field emplaced a block of brittle granitic rock on top of organic. Characterization of a fractured basement reservoir using highresolution 3d seismic and logging datasets. Pdf the challenge in oil and gas exploration has now shifted due to increasingly difficult to get back up economic value in a conventional. Fracture orientation is distributed using statistical model of fisher. Fractured basement reservoirs differ from other types of naturally fractured reservoirs in that they are generally considered to have no primary porosity le van hung et al. In the southern gulf of suez, egypt, several oil fields have been produced hydrocarbon from fractured basement, such as zeit bay, hilal, ashrafi and. Polymer injection as a possible eor method for a fractured. The most difficult problem after finding basement rock reservoirs is to evaluate.
Borehole images from acoustic or electrical scanning tools provide statistics of the fracture distribution, first order estimates of fracture opening and porosity, and a basis for. Understanding basement fracture architecture in padra. Fractured basement reservoir identification using geophysical. Fractured basement reservoir characterization for fracture.
Kantaatmaja formation evaluation society of malaysia fesm about the course this fiveday workshop introduces the principle of formation evaluation in fractured reservoir especially in petrophisic. Improving seismic image and impedance inversion of the texas panhandle fractured basement reservoir. Lithology is often an important control over reservoir quality normally assumed to be fairly uniform basement l l l. In the beruk northeast field, the quartzites are by far the best reservoirs. Fractured basement reservoir is unconventional hydrocarbon reservoir where hydrocarbon storage and conductivity are provided by fracture system associated with faults. Characterization of fractured basement rese rvoir using. Over the last 12 years, hurricane energy have explored and evaluated the potential of the basement play, west of shetland. Understanding basement fracture architecture in padra field, south cambay basin, india, through fullazimuth imaging. In fractured basement reservoirs, additional hydrocarbon potential can be found outside of structural closure as oil backfills down through the highly permeable fracture network, a highly attractive characteristic proven by hurricane energy. Fractured and weathered basement reservoirs search and. The paper aims to introduce a unique approach for study of basement reservoirs. If successful, output is expected to reach around 17,000bld once the. This conference will explore the many ways in which the geology of fractures is fundamental to the understanding of fluid flow in the subsurface, and hence to predicting and monitoring reservoir performance. Fractured reservoirs pose formidable difficulties for estimating reserves.
An application of the constrained conjugategradients leastsquares migration thang ha, kurt marfurt, and bin lyu university of oklahoma summary seismic inversion has become almost routine in quantitative 3d seismic interpretation. Apr 08, 2019 the momentum contrasts with past decades when fractured basement reservoirs were dismissed as too difficult or just plain nonreservoir. The unconventional fractured granite basement reservoirs of the cuu long basin in offshore southern vietnam have proven to be very successful structural oil plays. We will discuss how to use these times to pilot new products and technologies and thus position innovative companies to boom when conditions improve. May 22, 2019 fractured basement hydrocarbon reservoirs are recognized worldwide, but they are relatively poorly understood and underexploited trice, 2014. Rethink reservoirs and push paradigm shifts that will result in breakthroughs. Characterization of a fractured basement reservoir using high. Data acquired by hurricane energy through drilling and drill stem testing of five wells on the lancaster field has. Apr 04, 2014 fractured reservoirs require a different workflow to clastic reservoirs and basement is no exception.
The geological society of london the geology of fractured. The fractured basement reservoir is the one, in which fractures provide the essential porosity and permeability. The high permeabilities of the fractures effectively short circuits the matrix blocks, making it difficult to establish sufficiently high pressure gradients to allow effective viscous displacement of the oil in the matrix a new important effect comes into play imbibition. Naturally fractured reservoirs present a production paradox. Permeability for the fractured basement reservoirs, paper spe 88478. The term basement is used for a range of intrusive or extrusive igneous and metamorphic rocks beneath an unconformity at the base of a sedimentary sequence. Role of tectonics in development of fractured basement. Understanding of reservoir compartmentalization and its. Vairavan, ongc summary mumbai high structure is a giant hydrocarbon field with miocene carbonate as primary reservoirs and the fractured basement and basal clastics as secondary reservoirs. They are also notorious for early gas or water breakthrough. Fractured basement hydrocarbon reservoirs are recognized worldwide, but they are relatively poorly understood and underexploited trice, 2014. In fractured reservoirs viscous displacement often fails.
Individual wells in these fractured basement reservoirs are capable of sustained production in excess of 20,000 bblsd. When basement structures are deformed through tectonic action, seismicscale faults and subseismicscale fractures and fracture networks are created. Under the right conditions, significant volumes of hydro carbons can accumulate in the void space created by these basement fractures. The lancaster fractured basement is classified as a type 1 naturally fractured reservoir nfr, as it contains little to no intergranular matrix porosity or permeability and, as such, the reservoir behaviour is entirely dominated by the fracture network. The nature of naturally fractured reservoirs schlumberger. In a recent book, nelson 2001 gives a list of some 370 fields where natural fractures are important for production and a significant proportion are in basement rocks. The mesozoic granite basement in the cuu long basin of southern offshore vietnam experienced several major tectonic deformations which resulted in development of multiple fracture and fault systems within.
For a locally available biochemical polymer two properties, i. Pdf fracturedbasement reservoir modeling using continuous. As production from the ukcs continues to decline, and with the exploration potential of more traditional plays becoming increasingly mature. In such plays, oil migrates laterally from an organicrich source rock into a subsurface paleohigh of fractured crystalline basement, forming a socalled buried hill trap biddle and wielchowsky. Study oncharacteristics and development law of fractured basement reservoirs. In some fields, these fractured reservoirs can be extremely productive, whilst. Fractured basement reservoir characterization in dayung field. Type 2 vs type 1 tectonic fractured reservoirs cenozoic asmari fields, zagros dual porosity reservoirs type 2 hydrocarbon storage capacity is given by micro and vuggy matrix porosity systems, whilst deliverability is provided by networks of fissures. The term basement is used for a range of intrusive or extrusive igneous and metamorphic rocks beneath an. Fractured basement in mature basin exploration search and. Fractured carbonate reservoirs american association of. Peristiwa penemuan basement fractured yang berlaku sebagai batuan reservoir dalam industri hidrokarbon. People were quite rude and disparaging to me personally and the company even until about 2017, says trice.
The lancaster fractured basement is classified as a type 1 naturally fractured reservoir nfr, as it contains little to no intergranular matrix porosity or. Fractured basement considerations basement is defined as the crystalline igneous or metamorphic rock underlying the sedimentary cover. This study presents a characterization of fractured basement reservoir by using statistical and fractal methods with outcrop data, seismic data, as well as fmi log data. Reserves estimation of fractured reservoirs petrowiki. Hydrocarbon distribution in tight fractured reservoirs will be. Paper spe 80541 presented at the spe asia pacific oil and gas conference andexhibition, jakarta, 911 september. Fractured basement characteristics oil storage and mobility entirely depends on the fracture network recovery dominated by fracture network recovery dominated by rock properties type i type ii type iii type iv matrix porosity matrix permeability low high low high definitions of naturally fractured reservoirs, after nelson 2001 type 1. Characterization of fractured basement reservoir using. Penemuan potensi hidrokarbon dengan jumlah yang sangat besar telah ditemukan di batuan reservoir yang secara natural telah mengalami keretakan atau patahan fractured saat ini. Although basement reservoir plays have been exploited for decades, since the mid90s there. Fractured basement an overlooked play type with strong. An integrated approach for fractured basement characterization. The porosity and permeability of basement reservoirs depend on the structural location and hydrothermal and authigenic precipitates developed during and after the basin formation.
The weathered and leached and fractured zones are the main basement reservoirs in the study area. A large proportion of the worlds oil and gas is produced from fractured reservoirs, with new discoveries continuing to be made and put into development. A large portion of the worlds oil reserves is found in naturally fractured reservoirs. A case study of the sabatayn basin, yemen october 2018 plos one 10. Fractured basement reservoir yang sedang belajar geologi. Characterization of a fractured basement reservoir using. The kotopanjang area was chosen for this study because of good quality outcrops of pretertiary basement of the. Fractured basement reservoirs are most commonly defined as metamorphic and igneous rocks unconformably overlain by a sedimentary sequence, where faulting has led to the creation of a natural fracture network where hydrocarbons can accumulate.
Clair 2067a2, a quartz and a calcite fracture fill cutting precambrian basement granite, depth 2599. Here, we also consider basement rocks to include those of sedimentary origin with little or no matrix. The outcome of experimental and theoretical investigation to determine the critical production rate for single and multi fractured system, the capillary pressure effect, and the breakthrough time presented. Fractured reservoirs require a different workflow to clastic reservoirs and basement is no exception. Reservoirs in the basement is one type of reservoir that begins to be seen and is of particular concern in oil and gas exploration because it has. Oil is stored within the fracture network rather than in pore space within the rock, as would be seen in most other reservoirs. Geo expro vietnam improved images of fractured basement. To date, naturally fractured crystalline basement reservoirs basement in the uk continental shelf ukcs have been underexplored and underexploited. Natural fracture propping and earthquakeinduced oil migration in fractured basement reservoirs holdsworth, r.
Characterizing permeability for the fractured basement reservoirs. Improving seismic image and impedance inversion of the. The presence of fractured basement reservoirs has been reported within the hydrocarbon industry for decades and regarded previously as noneconomic gutmanis, 2005. Best practices for exploration dqg production examples iurp usa, venezuela, and brazil tako koning1. Although it is not common that hydrocar bons are retrieved from crystalline basement rocks, naturally fractured basement reservoirs have been. They include reservoirs with low hydrocarbon recovery.
In the statistical method, fracture intensity and length have been calculated from various outcrop data. The associated fracture meshwork greatly enhances reservoir quality. Understanding basement fracture architecture in padra field. Understanding basement fracture architecture in padra field, south. The optimum statistical distribution functions of fracture length for outcrops have been identified with the use of. Low porosity fractured reservoirs have been successfully described, using a combination of high resolution geometrical information from borehole images, together with deeper penetrating log evaluation methods. The basement of the rona ridge is comprised of granitic rocks which have been dated at between 2. Emplacement and biodegradation of oil in fractured basement. Detection and characterization of fractures in reservoirs is of. Here, we also consider basement rocks to include those of sedimentary origin with little or no matrix porosity north, 1990, such as the cambro. Formation evaluation in fractured basement reservoir instructor.
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