Coiled-Tubing Fracturing Increases Deliverability, Recoverable Reserves, and NPV of Infill Development Wells in a Mature Shallow Gas Field

2002 ◽  
Author(s):  
Stanley F. Wolny ◽  
Glen Schiffner ◽  
Eric G. Schmelzl ◽  
Merrill Jamieson ◽  
Marty Stromquist
2020 ◽  
Author(s):  
Abdulqawi Alfakih ◽  
Amir Galaby ◽  
Robert Famiev ◽  
Nauman Sadiq
Keyword(s):  

2003 ◽  
Vol 20 (1) ◽  
pp. 691-698
Author(s):  
M. J. Sarginson

AbstractThe Clipper Gas Field is a moderate-sized faulted anticlinal trap located in Blocks 48/19a, 48/19c and 48/20a within the Sole Pit area of the southern North Sea Gas Basin. The reservoir is formed by the Lower Permian Leman Sandstone Formation, lying between truncated Westphalian Coal Measures and the Upper Permian evaporitic Zechstein Group which form source and seal respectively. Reservoir permeability is very low, mainly as a result of compaction and diagenesis which accompanied deep burial of the Sole Pit Trough, a sub basin within the main gas basin. The Leman Sandstone Formation is on average about 715 ft thick, laterally heterogeneous and zoned vertically with the best reservoir properties located in the middle of the formation. Porosity is fair with a field average of 11.1%. Matrix permeability, however, is less than one millidarcy on average. Well productivity depends on intersecting open natural fractures or permeable streaks within aeolian dune slipface sandstones. Field development started in 1988. 24 development wells have been drilled to date. Expected recoverable reserves are 753 BCF.


1991 ◽  
Vol 14 (1) ◽  
pp. 387-393 ◽  
Author(s):  
C. R. Garland

AbstractThe Amethyst gas field was discovered in 1970 by well 47/13-1. Subsequently it was appraised and delineated by 17 wells. It consists of at least five accumulations with modest vertical relief, the reservoir being thin aeolian and fluviatile sandstones of the Lower Leman Sandstone Formation. Reservoir quality varies from poor to good, high production rates being attained from the aeolian sandstones. Seismic interpretation has involved, in addition to conventional methods, the mapping of several seismic parameters, and a geological model for the velocity distribution in overlying strata.Gas in place is currently estimated at 1100 BCF, with recoverable reserves of 844 BCF. The phased development plan envisages 20 development wells drilled from four platforms, and first gas from the 'A' platforms was delivered in October 1990. A unitization agreement is in force between the nine partners, with a technical redetermination of equity scheduled to commence in 1991.


1994 ◽  
Author(s):  
S. L. West ◽  
P. J. R. Cochrane

Tight shallow gas reservoirs in the Western Canada Basin present a number of unique challenges in accurately determining reserves. Traditional methods such as decline analysis and material balance are inaccurate due to the formations' low permeabilities and poor pressure data. The low permeabilities cause long transient periods not easily separable from production decline using conventional decline analysis. The result is lower confidence in selecting the appropriate decline characteristics (exponential or harmonic) which significantly impacts recovery factors and remaining reserves. Limited, poor quality pressure data and commingled production from the three producing zones results in non representative pressure data and hence inaccurate material balance analysis. This paper presents the merit of two new methods of reserve evaluation which address the problems described above for tight shallow gas in the Medicine Hat field. The first method applies type curve matching which combines the analytical pressure solutions of the diffusivity equation (transient) with the empirical decline equation. The second method is an extended material balance which incorporates the gas deliverability theory to allow the selection of appropriate p/z derivatives without relying on pressure data. Excellent results were obtained by applying these two methodologies to ten properties which gather gas from 2300 wells. The two independent techniques resulted in similar production forecasts and reserves, confirming their validity. They proved to be valuable, practical tools in overcoming the various challenges of tight shallow gas and in improving the accuracy in gas reserves determination in the Medicine Hat field.


1991 ◽  
Vol 14 (1) ◽  
pp. 503-508 ◽  
Author(s):  
Robert A. Lambert

AbstractThe Victor gas field lies in the Southern North Sea Gas Province on the eastern flank of the Sole Pit Basin. The field straddles Blocks 49/17 and 49/22, and is situated approximately 140 km off the Lincolnshire coast. Victor was discovered in April 1972 and is operated by Conoco (UK) Ltd on behalf of BP, Mobil and Statoil. The structure is an elongated tilted fault block, trending NW-SE. The reservoir sands are contained in the Leman Sandstone Formation (Rotliegendes Group) of Early Permian age, and consist mainly of stacked aeolian and fluvial sands with a gross thickness of 400-450 ft across the field. Porosities vary from 16-20%, with permeabilities ranging from 10 md to 1000 md in the producing zones. Initial gas in place is estimated at about 1.1 TCF with recoverable reserves of the order of 900 BCF. The field was brought on-stream in October 1984, and the five producing wells deliver, on average, 200 MMSCFD through the Viking Field 'B Complex' to the Conoco/BP terminal at Theddlethorpe in Lincolnshire


2018 ◽  
Vol 913 ◽  
pp. 355-361
Author(s):  
Zhong Wen Yang ◽  
Hong Bin Li ◽  
Jing Li Wang ◽  
Zong Yue Bi

According to the demand of oil and gas field development with a small amount of hydrogen sulfide, CT80S sulfur resistance coiled tubing was developed through the raw materials and manufacturing technology. The microstructure, mechanical properties, fatigue life and corrosion resistance of the CT80S sulfur resistant coiled tubing were analyzed. The results showed that the microstructure of CT80S sulfur resistant coiled tubing was consisted of the ferrite and pearlite with the grain size of 12, banded structure of 1.0, and the inclusions was less than 1.0. The strength and hardness of the pipe meet the requirements of API Spec 5ST, and the hardness control was less than 18HRC. The pipe had excellent low cycle fatigue property, the mean fatigue life of Φ31.8 × 3.18mm tube was 1055 cycles when the internal pressure was 34.47MPa and the bending radius was 1219mm. According to NACE TM 0284 and NACE TM 0177 standard, the HIC and SCC performance tests were carried out in same solution. The results show that the developed tubing is insensitive to HIC and the resistance to sulfide stress corrosion is good, under 90%σs stress loading not break.


2003 ◽  
Vol 20 (1) ◽  
pp. 97-105 ◽  
Author(s):  
G. Cowan ◽  
T. Boycott-Brown

abstractThe North Morecambe Gas Field in the East Irish Sea Basin was discovered by well 110/2-3 in 1976 and contains ultimately recoverable reserves of over one TCF. THe structure is fault closed on three sides and dip closed to the north. Development was by ten conventionally drilled high angle deviated wells, from a not normally manned platform. Gas is exported through a dedicated pipeline to a new terminal at Barrow. The Triassic Sherwood Sandstone Group reservoir is composed of sandstones deposited in a semi-arid, fluvial and aeolian setting. Thin aeolian sandstones dominate flow into the well bore. Platy illite reduces the permeability by two to three orders of magnitude in the lower, illite affected zone of the reservoir, RFT measurements from the first development well proved that the free water level was 25 feet higher than expected, giving a maximum gas column of 975 feet. Re-mapping after drilling has shown that 56% of the GIIP is contained in the high permeability illite-free zone.


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