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Helium survey—identification of “sweet spots” locations for exploratory, appraisal and production drilling. November, 2009. Executive summary.
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Helium survey—identification of “sweet spots” locations for exploratory, appraisal and production drilling November, 2009
Executive summary • During exploration, appraisal and development of oil and gas fields with complex geology, such as fracturing permeability, low continuity of thickness and porosity formations, energy companies face an ever present problem of low drilling success. • Traditional exploration technologies such as seismic do not always accurately predict hydrocarbons saturation. • In a review of more than 2600 US and international wildcat wells – all drilled after completion of geochemical or non-seismic hydrocarbon detection surveys- more than 80% of wells drilled on prospects associated with positive hydrocarbon anomalies resulted in commercial discoveries; and only 11% of wells drilled on prospects not associated with such anomalies resulted in discoveries*. • Actual Geology can identify an active petroleum system in the exploration area, generate unique non-seismic leads for further geological and seismic evaluation and identify “sweet spots”. • Our methods are non-invasive and have a minimal environmental impact. * presentation at 2008 AAPG International Conference and Exhibition, Cape Town, South Africa, October 26-29, 2008
Outstanding track record • 50 completed projects covering over 30,000 sq km in the last 8 years • Strong in-house analytical team interpreting helium survey results for clients • Clients: Gazprom, Rosneft, Lukoil, Yukos, Norilsk Nickel and many others.
Our services Actual Geology services fit well into an integrated exploration strategy by detecting occurrences of hydrocarbons’ by-products, such as helium, which serve as indicators to the location of undiscovered oil and gas accumulations. Actual Geology provides: Mapping of helium concentration and subsequent forecasting of reservoir properties. Prediction of section saturation before drilling. Determination of areas with improved fractured permeability in prospective reservoirs or producing deposits. Prediction of reservoir distribution, delineation of oil and gas accumulations. Determination of residual reserves at mature fields with declining production. Identification of prospective drilling targets, cut off of the low prospects and high risk zones.
The process Preliminary stage(field): Helium survey 300x300m grid, or 100x100m grid Data processing Preliminary data interpretation Stage one(field): Identification of helium anomalies Helium survey 100x100m grid, or 25x25m grid Stage two: (analytical) Final mappingof helium anomalies Data interpretation Data processing
Timeframe Once equipment and the team (20 detectors and 50 field specialists) are on site an average survey duration over an area of 100 km² is 60 days including: Deployment and deconstruction of field camp, testing of field equipment – 5 days Helium measurements on 100х100 m grid – 14 days Preliminary field data processing and planning of detailed grid – 4 days Helium measurements on detailed grid (15% of total area) – 7 days Final data processing and interpretation of the results –25 days Contingency work (10%) - 5 days Production rate of one team – 30-40 sampling points per day Equipment example: PHD-4 Portable Helium Detector
1. Equipment and tools: Helium leak detectors and gas analyzers Computers and specially designed/developed software for operational in-field quality control and processing Satellite communications between detectors and server holding central database minimizes human intervention and possible errors GPS- enabled equipment for accurate positioning and recording 2. Locally purchased (rented) equipment: Cross-country vehicles Field equipment (sleepers, office, kitchen, generator, etc.) Water, food and fuel supply tracks 3. Personnel Initially – qualified Actual Geology specialists Support personnel– locally hired Future development – recruitment and training of local staff Field work logistics Mobile laboratory (a) and field equipment (b) versions
Theoretical foundations All petroleum basin exhibit surface or near-surface hydrocarbon gases leakage. Helium on Earth is mostly created by the natural radioactive decay of heavy radioactive elements (thorium and uranium). Helium is a noble gas, chemically inert and is nonabsorbent into surrounding rocks and doesn’t form compounds. Helium’s ability for migration is greater than of other gases, with the exception of hydrogen. Helium migrates along the tectonic faults and through high-fractured zone. Seals, such as clay rocks, are not an obstacle for helium migration. Increased concentrations of helium in the near surface zone are the projections of zones with higher helium gas-saturation and improved permeability of geological section. The average helium concentrations are: 0.65 ml/l - in bottom water of hydrocarbon accumulations; 7 ml/l - in oil pools; 100 ml/l - in gas pools (ml/l – milliliters per liter). Helium concentration - residual oil saturation relationship Helium concentration Oil saturation
Theoretical foundations Different vertical sections of helium concentration in the case of presence(b) or absence(a) of hydrocarbon accumulations within sedimentary cover. As helium solubility is so much greater in hydrocarbon pools than in water, reservoir is saturated by helium and it’s concentration increases (Fig.1, b). Near-earth surface helium concentrations is greater in case of hydrocarbon pool presence in geological section (b) in comparison with case where pool is absent (a).
Conclusions The results of helium surveying leads to significantly better prediction, therefore risk and cost reduction Helium surveying is a powerful complement to conventional exploration methods. Further integration with available seismic, logging and production data can help companies to identify residual reserves, enhance potential of declining production or flooded fields, better plan drilling operations (especially horizontal wells) during exploration, appraisal and development stages In order to assess and prove effectiveness of its methods Actual Geology can conduct a pilot survey on an already explored field where a number of wells have been drilled in order to compare helium survey results with company’s existing information Helium surveying is a reliable and proven (by a number of successful projects in various geological settings) technique for accurate identification of the best drilling locations. Our experienced specialists are able to work in practically any complex terrain, traditionally off-limits due to restricted accessibility
Contacts London Maxim Golodnitsky Project Manager Suite 3, Barkat House 116-118 Finchley Road London, England NW3 5HT Tel. +44 (0)20 7433 2512 Fax. +44 (0)20 7692 7957 E-mail: maxim@actualgeology.com St Petersburg Viktor Chistiakov General Director 36 Rubinstein street, office 35, St. Petersburg 191002 Russia Tel. +7 (812) 347 78 19 Fax. +7(812)5718398 E-mail: v.chistyakov@actualgeology.ru