The design and application of a polymer EOR trial on Barrow Island

2010 ◽  
Vol 50 (2) ◽  
pp. 702
Author(s):  
Wisnu Widjanarko ◽  
Paul Welton ◽  
Daniel Leòn Echeverría ◽  
Lina Hartanto ◽  
John Scott ◽  
...  
Keyword(s):  
Scale Up ◽  
Field Application ◽  
Petroleum Engineering ◽  
Low Permeability ◽  
High Porosity ◽  
Fine Grained ◽  
Well Spacing ◽  
Chemical Eor ◽  
Induced Fractures ◽  
Design And Application

The design and application of a chemical EOR pilot for a complex, low-permeability waterflood will be presented. Our focus has been on developing appropriate field application options, allowing flexibility of operation against a background of reservoir complexity and uncertainty. Australia’s Barrow Island Windalia reservoir, the nation’s largest onshore waterflood, was developed in the late 1960s. Cumulative oil production to date is over 288 MMSTBO. Planning a chemical EOR scheme needs to address the following reservoir and production characteristics: highly heterogeneous, very fine grained, bioturbated argillaceous sandstone, high in glauconite; high porosity (0.28) but low permeability (5 mD with 20 mD+ streaks); production and injection necessarily stimulated by induced fractures highly saline and hard brine; and, large waterflood pattern volumes (10 MMbbl at 20 acre well spacing). Initial screening recommended that polymers be considered for sweep improvement and conformance control, although reservoir complexity presented a challenge. In this paper, we summarise the subsurface studies, and subsequent petroleum engineering and facilities design, which lead to the successful pilot start-up in May 2009. In particular, we discuss the implications on design and operation of a pilot in a Class A nature reserve. Results from the proposed polymer pilot flood will allow assessment of further chemical EOR applications and potential field-wide scale-up.

Mechanism of Overpressure Formation in Deeply Burial Sandstone

2013 ◽  
Vol 295-298 ◽  
pp. 2736-2739
Author(s):  
Hai Yan Hu
Keyword(s):  
Hydrostatic Pressure ◽  
Capillary Pressure ◽  
Driving Force ◽  
Low Permeability ◽  
Gas Generation ◽  
Tight Sandstone ◽  
Gas Accumulation ◽  
Fine Grained ◽  
Sandstone Reservoirs ◽  
Induced Fractures

Overpressure is often encountered in the Jurassic tight and the overpressure is closely associated with gas generation. The pressure transfer from the over-pressurized mudstones to adjacent tight sandstones might occur through overpressure induced-fractures. The fine-grained coal containing Jurassic sandstone is sensitive to compaction, and the porosity decreases dramatically with the increase of overlying load. As gas migrates into the tight sandstones, it must overcome the capillary pressure which is greater than the hydrostatic pressure. The gas charging pressure in the tight sandstone must be higher than the capillary pressure, resulting in an overpressure buildup within the tight sandstones. Gas shows, low permeability and strong diagenesis in the overpressure of the tight sandstone system have been observed. Additionally, capillary seals are identified as playing an important role in the mechanism of the overpressure formation in tight sandstone reservoirs. Overpressure might be a driving force to create induced fractures in the interval, which has applications for crossing-formation migration and gas accumulation.

A New well Pattern for Enhancing Waterflood Performance of Ultra-Low Permeability Reservoir in Changqing Oilfield

2013 ◽  
Vol 318 ◽  
pp. 501-506
Author(s):  
Zhang Zhang ◽  
Shun Li He ◽  
Hai Yong Zhang
Keyword(s):  
Oil Recovery ◽  
Early Stage ◽  
Water Injection ◽  
Field Application ◽  
Low Permeability ◽  
Great Ability ◽  
Low Permeability Reservoir ◽  
Well Spacing ◽  
Well Pattern ◽  
The One

Because the development of ultra-low permeability reservoir is relative to fracture system, suitable well pattern arrangement is very significant for effective flooding management. There were three kinds of well pattern used to waterflood in Changqing oilfield: square inverted nine-spot, rhombus inverted nine-spot and rectangular five-spot pattern, according to the degree of fracture growth. In view of the defects of these well patterns in the development of ultra-low permeability reservoirs, a new well spacing concept is developed. Numerical simulations are carried out to illustrate the adaptability and strong points of this new well pattern. For this well pattern, on the one hand, the distance between producers and injectors along the fracture direction is widened and thus massive fracturing can be conducted to enhance oil productivity and water injection, and on the other hand, a high producer/injector ratio ensures high oil recovery rate in early stage. Besides, this new well pattern has a great ability of adjustment. Field application showed a remarkably well producing performance.

Data-Driven Causal Analyses of Parent-Child Well Interactions for Well Spacing Decisions

2021 ◽  
Author(s):  
Rohan Sakhardande ◽  
Deepak Devegowda
Keyword(s):  
Causal Inference ◽  
Randomized Clinical Trials ◽  
Drug Efficacy ◽  
Complex Problem ◽  
Petroleum Engineering ◽  
Well Performance ◽  
Well Spacing ◽  
The Impact ◽  
Naive Approach ◽  
Parent Child

Abstract The analyses of parent-child well performance is a complex problem depending on the interplay between timing, completion design, formation properties, direct frac-hits and well spacing. Assessing the impact of well spacing on parent or child well performance is therefore challenging. A naïve approach that is purely observational does not control for completion design or formation properties and can compromise well spacing decisions and economics and perhaps, lead to non-intuitive results. By using concepts from causal inference in randomized clinical trials, we quantify the impact of well spacing decisions on parent and child well performance. The fundamental concept behind causal inference is that causality facilitates prediction; but being able to predict does not imply causality because of association between the variables. In this study, we work with a large dataset of over 3000 wells in a large oil-bearing province in Texas. The dataset includes several covariates such as completion design (proppant/fluid volumes, frac-stages, lateral length, cluster spacing, clusters/stage and others) and formation properties (mechanical and petrophysical properties) as well as downhole location. We evaluate the impact of well spacing on 6-month and 1-year cumulative oil in four groups associated with different ranges of parent-child spacing. By assessing the statistical balance between the covariates for both parent and child well groups (controlling for completion and formation properties), we estimate the causal impact of well spacing on parent and child well performance. We compare our analyses with the routine naïve approach that gives non-intuitive results. In each of the four groups associated with different ranges of parent-child well spacing, the causal workflow quantifies the production loss associated with the parent and child well. This degradation in performance is seen to decrease with increasing well spacing and we provide an optimal well spacing value for this specific multi-bench unconventional play that has been validated in the field. The naïve analyses based on simply assessing association or correlation, on the contrary, shows increasing child well degradation for increasing well spacing, which is simply not supported by the data. The routinely applied correlative analyses between the outcome (cumulative oil) and predictors (well spacing) fails simply because it does not control for variations in completion design over the years, nor does it account for variations in the formation properties. To our knowledge, there is no other paper in petroleum engineering literature that speaks of causal inference. This is a fundamental precept in medicine to assess drug efficacy by controlling for age, sex, habits and other covariates. The same workflow can easily be generalized to assess well spacing decisions and parent-child well performance across multi-generational completion designs and spatially variant formation properties.

A Feasibility Study of Hybrid Thermal and Chemical EOR Methods in a Low-Permeability Carbonate Heavy Oil Reservoir with Strong Aquifer Drive

2018 ◽  
Author(s):  
Mohammed Taha Al-Murayri ◽  
Eman Hadad Fadli ◽  
Fawziya Mohammad Al-Shati ◽  
Ali Qubian ◽  
Zhitao Li ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Heavy Oil ◽  
Low Permeability ◽  
Oil Reservoir ◽  
Chemical Eor ◽  
Heavy Oil Reservoir

New Calculation Method of Sweep Efficiency after Pattern Infilling in Low Permeability Reservoir

2014 ◽  
Vol 1010-1012 ◽  
pp. 1713-1718
Author(s):  
Fang Zhao ◽  
Rui Shen ◽  
Gang Xu
Keyword(s):  
Calculation Method ◽  
Statistical Data ◽  
Effective Means ◽  
Low Permeability ◽  
Effect Evaluation ◽  
Sweep Efficiency ◽  
Well Spacing ◽  
Well Pattern ◽  
Development Effectiveness ◽  
Result Show

Sweep efficiency is a very important parameters for development effect evaluation and dynamic analysis of oilfield. For low permeability oilfield, well pattern thickening is one of the most effective means of improving development effectiveness. In this paper, a corrected calculation method is given and well spacing density is introduced as a parameter for the formula correction. The curve of volumetric sweep efficiency and well spacing density was achieved through the formula and statistical data. After the infill adjustment, increasing multiple of sweep efficiency can be calculated. Using the actual data of Changqing oilfield to calculate, result show that the deviation is 1.1% .

A New Formation Evaluation Technique for the Lower Tertiary in South Texas - Predicting Production in Low Permeability, Fine-Grained Sandstones

2004 ◽  
Author(s):  
John C. Rasmus ◽  
John P. Horkowitz ◽  
Thierry Chabernaud ◽  
Peter Graham ◽  
Malcolm Summers ◽  
...  
Keyword(s):  
South Texas ◽  
Low Permeability ◽  
Evaluation Technique ◽  
Formation Evaluation ◽  
Fine Grained ◽  
Lower Tertiary ◽  
New Formation

Wet Welding as a “Serious” Repair Procedure?

1998 ◽  
Vol 120 (3) ◽  
pp. 191-196 ◽  
Author(s):  
P. Szelagowski
Keyword(s):  
Welding Process ◽  
High Hardness ◽  
Field Application ◽  
Oil Field ◽  
Quality Data ◽  
Design Criteria ◽  
High Porosity ◽  
High Hydrogen ◽  
Research Activities ◽  
Welding Processes

Due to intensive and concentrated research activities during the last 10 to 15 yr, the quality of wet-welded joints has been improved to an extent that this process is currently regarded as a potential alternative to the more costly dry hyperbaric welding processes in comparable water depths. The wet welding process has matured to an interesting alternative repair process due to its high flexibility and versatility and its low investment costs with respect to achieving comparable weldment quality. However, due to the previous bad reputation of the poor weldment quality in former times, related to extremely high hardness, high porosity, high hydrogen contamination, and, in combination with this, high cracking susceptibility, the wet welding process still requires concentrated activities to improve its reputation and credibility, especially in European oil field application. New acceptance creiteria, more detailed information on the achievable weldment quality, and especially the development of life-predicting data for wet-welded components on the one hand, and new design criteria especially related to the process application in wet environment as well as excellent training of diver welders on the other hand, have been required. Advanced testing methods had to be applied, additional design criteria had to be developed, and achievable weldment quality data had to be included in acknowledged and approved standards and recommendations in training and certification standards for diver welders. All these data are now available. These results have been achieved with the financial support of the European Community through the THERMIE PROJECT FUNDING.

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