A Study to Prevent Bottom Water From Coning in Heavy-Oil Reservoirs: Design and Simulation Approaches

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Binshan Ju ◽  
Xiaofeng Qiu ◽  
Shugao Dai ◽  
Tailiang Fan ◽  
Haiqing Wu ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Bottom Water ◽  
Horizontal Wells ◽  
Oil Well ◽  
Vertical Wells ◽  
Water Contact ◽  
Water Columns ◽  
Heavy Oil Reservoirs ◽  
Oil Water ◽  
Downhole Water Sink

The coning problems for vertical wells and the ridging problems for horizontal wells are very difficult to solve by conventional methods during oil production from reservoirs with bottom water drives. If oil in a reservoir is too heavy to follow Darcy’s law, the problems may become more complicated for the non-Newtonian properties of heavy oil and its rheology. To solve these problems, an innovative completion design with downhole water sink was presented by dual-completion in oil and water columns with a packer separating the two completions for vertical wells or dual-horizontal wells. The design made it feasible that oil is produced from the formation above the oil water contact (OWC) and water is produced from the formation below the OWC, respectively. To predict quantitatively the production performances of production well using the completion design, a new improved mathematical model considering non-Newtonian properties of oil was presented and a numerical simulator was developed. A series of runs of an oil well was employed to find out the best perforation segment and the fittest production rates from the formations above and below OWC. The study shows that the design is effective for heavy oil reservoir with bottom water though it cannot completely eliminate the water cone formed before using the design. It is a discovery that the design is more favorable for new wells and the best perforation site for water sink (Sink 2) is located at the upper 1/3 of the formation below OWC.

scholarly journals Downhole electric heating of heavy-oil wells

2020 ◽  
Vol 10 (2) ◽  
pp. 61-72
Author(s):  
John Karanikas ◽  
Guillermo Pastor ◽  
Scott Penny
Keyword(s):  
Heavy Oil ◽  
Horizontal Wells ◽  
Electric Heating ◽  
Optimization Method ◽  
Economic Benefits ◽  
Production Optimization ◽  
Operating Conditions ◽  
Oil Reservoirs ◽  
Oil Well ◽  
Heavy Oil Reservoirs

Downhole electric heating has historically been unreliable or limited to short, often vertical, well sections. Technology improvements over the past several years now allow for reliable, long length, relatively high-powered, downhole electric heating suitable for extended-reach horizontal wells. The application of this downhole electric heating technology in a horizontal cold-producing heavy oil well in Alberta, Canada is presented in this paper. The field case demonstrates the benefits and efficacy of applying downhole electric heating, especially if it is applied early in the production life of the well. Early production data showed 4X-6X higher oil rates from the heated well than from a cold-producing benchmark well in the same reservoir. In fact, after a few weeks of operation, it was no longer possible to operate the benchmark well in pure cold-production mode as it watered out, whereas the heated well has been producing for twenty (20) months without any increase in water rate. The energy ratio, defined as the heating value of the incremental produced oil to the injected heat, is over 20.0, resulting in a carbon-dioxide footprint of less than 40 kgCO2/bbl, which is lower than the greenhouse gas intensity of the average crude oil consumed in the US. A numerical simulation model that includes reactions that account for the foamy nature of the produced oil and the downhole injection of heat, has been developed and calibrated against field data.  The model can be used to prescribe the range of optimal reservoir and fluid properties to select the most promising targets (fields, wells) for downhole electric heating as a production optimization method. The same model can also be used during the execution of the project to explore optimal operating conditions and operating procedures. Downhole electric heating in long horizontal wells is now a commercially available technology that can be reliably applied as a production optimization recovery scheme in heavy oil reservoirs. Understanding the optimum reservoir conditions where the application of downhole electric heating maximizes economic benefits will assist in identifying areas of opportunity to meaningfully increase reserves and production in heavy oil reservoirs around the world.

Assessment of Down-Hole Water Sink Technology for Controlling Water Inflow at Petroleum Wells

2004 ◽  
Vol 126 (4) ◽  
pp. 334-341 ◽  
Author(s):  
Andrew K. Wojtanowicz ◽  
Miguel Armenta
Keyword(s):  
Bottom Water ◽  
Water Inflow ◽  
Water Drainage ◽  
Gas Reservoirs ◽  
Water Contact ◽  
Hydrocarbon Production ◽  
Well Completion ◽  
Oil Water ◽  
Petroleum Wells ◽  
Downhole Water Sink

Water inflow to petroleum wells hampers production of oil or gas leading to early shut downs of the wells without sufficient recovery of hydrocarbons in place. Downhole water sink (DWS) is a completion/production technique for producing water-free hydrocarbons with minimum amount of water from reservoirs with bottom water drive and strong tendency to water coning. DWS eliminates water invasion to hydrocarbon production by employing hydrodynamic mechanism of coning control in situ at the oil-water or gas-water contact. The mechanism is based upon a localized water drainage generated by another well completion (downhole water sink) installed in the aquifer beneath the oil/water or gas/water contact. The paper summarizes the development and state-of-the-art of DWS technology. Presented are results from theoretical studies, physical and numerical experiments, and field projects to date. It is demonstrated that DWS could increase recovery and control water production in vertical and horizontal oil wells—with natural flow, downhole pumps or gas lift, and in the gas wells producing from low-pressure tight gas reservoirs. To date, DWS has been used in reservoirs with bottom water. Moreover, in principle, the technology might also be used in the dipping reservoir structures with encroaching side-water.

The Research and Application of Segregated Completion Technology in Horizontal Wells in the Heavy Oil Reservoirs

2014 ◽  
Vol 694 ◽  
pp. 350-353
Author(s):  
Zhen Yu Sun ◽  
Ji Cheng Zhao
Keyword(s):  
Heavy Oil ◽  
Horizontal Wells ◽  
Steam Injection ◽  
Thermal Recovery ◽  
Oil Reservoirs ◽  
Oil Well ◽  
Horizontal Section ◽  
Liaohe Oilfield ◽  
Heavy Oil Reservoirs ◽  
Injection Technology

Liaohe oilfield is the biggest production base of the heavy oil in China. There are more than 800 horizontal wells with thermal recovery in the heavy oil reservoirs. Most of them adopt screen to complete the wells without packer outside of the casing, which results in packing off annulus space between screen and layer and only commingled steam or step steam can be injected inside the screen. Because of the areal and vertical anisotropy of the reservoirs, the horizontal sections are exploited unequally. According to the statistics, the horizontal wells with nonuniform exploitation accounts for 80 percent of all the horizontal wells with thermal recovery, and only 1/3 to 1/2 of the horizontal sections are comparatively well produced. The oil well productivity is seriously affected. So based on step steam injection inside the screen, we have developed the segregated completion and segregated steam injection technology applied to the horizontal wells with thermal recovery in heavy oil reservoirs. By means of the research on the segregated completion technology and development of high temperature ECP and casing thermal centralizer, which formed the corresponding technology applied in the horizontal wells with thermal recovery. Till now this technology has been applied in 8 wells, and average cyclic steam/oil ratio increased 0.1 plus, and the uniform development level of the horizontal section has been improved and the oilfield’s development effect has been advanced obviously.

Non-Darcy Binomial Deliverability Equations for Partially Penetrating Vertical Gas Wells and Horizontal Gas Wells

2009 ◽  
Author(s):  
Tao Zhu ◽  
Jing Lu
Keyword(s):  
Bottom Water ◽  
Horizontal Wells ◽  
Vertical Wells ◽  
Gas Wells ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Well ◽  
Increase Productivity ◽  
Flow Domain ◽  
Inflow Performance

Many gas reservoirs are with bottom water drive. In order to prevent or delay unwanted water into the wellbore, the producing wells are often completed as partially penetrating vertical wells, and more and more horizontal wells have been drilled in recent years in bottom water drive gas reservoirs to reduce water coning and increase productivity. For a well, non-Darcy flow is inherently a near wellbore phenomenon. In spite of the considerable study that non-Darcy behavior of fully penetrating vertical wells, there has been no study of a partially penetrating vertical well or a horizontal well in a gas reservoir with bottom water drive. This paper presents new binomial deliverability equations for partially penetrating vertical gas wells and horizontal gas wells, assuming that only radial flow occurs in the near wellbore non-Darcy’s flow domain. The inflow performance of a vertical gas well is compared with that of a horizontal gas well. The proposed equations can account for the advantages of horizontal gas wells.

Pressure Maintenance and Improving Oil Recovery by Means of Immiscible Water-Alternating-CO2 Processes in Thin Heavy-Oil Reservoirs

2013 ◽  
Vol 16 (01) ◽  
pp. 60-71 ◽  
Author(s):  
Sixu Zheng ◽  
Daoyong Yang
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Oil Production ◽  
Horizontal Wells ◽  
Operating Conditions ◽  
Oil Reservoirs ◽  
Oil Saturation ◽  
Water Alternating Gas ◽  
Heavy Oil Reservoirs ◽  
Water Cut

Summary Techniques have been developed to experimentally and numerically evaluate performance of water-alternating-CO2 processes in thin heavy-oil reservoirs for pressure maintenance and improving oil recovery. Experimentally, a 3D physical model consisting of three horizontal wells and five vertical wells is used to evaluate the performance of water-alternating-CO2 processes. Two well configurations have been designed to examine their effects on heavy-oil recovery. The corresponding initial oil saturation, oil-production rate, water cut, oil recovery, and residual-oil-saturation (ROS) distribution are examined under various operating conditions. Subsequently, numerical simulation is performed to match the experimental measurements and optimize the operating parameters (e.g., slug size and water/CO2 ratio). The incremental oil recoveries of 12.4 and 8.9% through three water-alternating-CO2 cycles are experimentally achieved for the aforementioned two well configurations, respectively. The excellent agreement between the measured and simulated cumulative oil production indicates that the displacement mechanisms governing water-alternating-CO2 processes have been numerically simulated and matched. It has been shown that water-alternating-CO2 processes implemented with horizontal wells can be optimized to significantly improve performance of pressure maintenance and oil recovery in thin heavy-oil reservoirs. Although well configuration imposes a dominant impact on oil recovery, the water-alternating-gas (WAG) ratios of 0.75 and 1.00 are found to be the optimum values for Scenarios 1 and 2, respectively.

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