Alkinani, Husam H. (Missouri University of Science and Technology) | Al-Hameedi, Abo Taleb T. (Missouri University of Science and Technology) | Dunn-Norman, Shari (Missouri University of Science and Technology) | Flori, Ralph E. (Missouri University of Science and Technology) | Alsaba, Mortadha T. (Australian College of Kuwait) | Amer, Ahmed S. (Newpark Technology Center/ Newpark Drilling Fluids)
Oil/gas exploration, drilling, production, and reservoir management are challenging these days since most oil and gas conventional sources are already discovered and have been producing for many years. That is why petroleum engineers are trying to use advanced tools such as artificial neural networks (ANNs) to help to make the decision to reduce nonproductive time and cost. A good number of papers about the applications of ANNs in the petroleum literature were reviewed and summarized in tables. The applications were classified into four groups; applications of ANNs in explorations, drilling, production, and reservoir engineering. A good number of applications in the literature of petroleum engineering were tabulated. Also, a formalized methodology to apply the ANNs for any petroleum application was presented and accomplished by a flowchart that can serve as a practical reference to apply the ANNs for any petroleum application. The method was broken down into steps that can be followed easily. The availability of huge data sets in the petroleum industry gives the opportunity to use these data to make better decisions and predict future outcomes. This paper will provide a review of applications of ANNs in petroleum engineering as well as a clear methodology on how to apply the ANNs for any petroleum application.
Guo, Hu (China University of Petroleum, Beijing) | Li, Yiqiang (China University of Petroleum, Beijing) | Kong, Debin (China University of Petroleum, Beijing) | Ma, Ruicheng (China University of Petroleum, Beijing) | Li, Binhui (China University of Petroleum, Beijing) | Wang, Fuyong (China University of Petroleum, Beijing)
Although the alkali/surfactant/polymer (ASP) flooding technique used for enhanced oil recovery (EOR) was put forward many years ago, it was not until 2014 that it was first put into practice in industrial applications with hundreds of injectors and producers in the Daqing Oil Field in China. In this study, 30 ASP-flooding field tests in China were reviewed to promote the better use of this promising technology. Up to the present, ASP flooding in the Daqing Oil Field deserves the most attention.
Alkali type does affect the ASP-flooding effect. Strong alkali [using sodium hydroxide (NaOH)] ASP flooding (SASP) was given more emphasis than weak alkali [using sodium carbonate (Na2CO3)] ASP flooding (WASP) for a long time in the Daqing Oil Field because of the lower interfacial tension (IFT) of the surfactant and the higher recovery associated with NaOH than with Na2CO3. Other ASP-flooding field tests completed in China all used Na2CO3. With progress in surfactant production, a recent large-scale WASP field test in the Daqing Oil Field produced an incremental oil recovery nearly 30% higher than most previous SASP recoveries and close to the value of the most-successful SASP test. However, the most-successful SASP test was partly attributed to the weak alkali factor. Recent studies have shown that the WASP incremental oil recovery factor could be as good as that of SASP but with much-better economic benefits.
Screening of surfactant by IFT test is very important in the ASP-flooding practice in China. Whether dynamic or equilibrium IFT should be selected as criteria in surfactant screening is still in dispute. Many believe the equilibrium IFT is more important than the dynamic IFT in terms of the displacement efficiency; thus, it is better to choose a lower dynamic IFT when the equilibrium IFT meets the 10–3 order-of-magnitude requirement. However, it is impossible for many surfactants to form ultralow equilibrium IFT. Because of the low acid value of the Daqing crude oil, the asphaltene and resin components play a very important role in reducing the oil/water IFT and asphaltene is believed to be more influential, although more work is required to resolve this controversial issue.
Whether polymer viscoelasticity can reduce the residual oil saturation is still a matter of debate. Advances in surfactant production and in the overcoming of scaling and produced-fluid-handling challenges form the foundation of the industrial application of ASP flooding. Further work is advised on the emulsification effect of ASP flooding. According to one field test, the EOR routine should be selected depending on consideration of the residual oil type to decide whether to increase the sweep volume and/or displacement efficiency. The micellar flooding failure in one ASP field test in China has led all subsequent field tests in China to choose the “low concentration, large slug” technical route instead of the “high concentration, small slug” one. ASP flooding can increase oil recovery by 30% at a cost of less than USD 30/bbl; thus, this technique can be used in response to low-oil-price challenges.
Oily sludge is one of the main wastes produced during oilfield development. The composition of oily sludge is complex, resulting in difficult separation and high processing cost. The existing technologies such as landfill, microbiological deterioration, heat treatment and solvent extraction are difficult to meet the needs of oily sludge treatment. It is necessary to develop a highly efficient and cheap reutilization technology for oily sludge. For this reason, we have proposed to recycle the oily sludge which can be utilized to profile control in water injection and thermal recovery wells.
In the process of research, we have developed five aspects of work: First, three-phase separation of oily sludge was carried out by distillation, and water quality, oil-phase composition and solid particle size were analyzed. The compatibility of oily sludge and oil reservoir was investigated. Second, the mechanism and influence factors of the oily sludge for profile control were studied by long core model test and microscope observation. Third, suspension analysis and mobility analysis were developed on oily sludge, and experimental results were used to research oily sludge profile control agent. Fourth, numerical simulation was used to optimize the engineering design of Oily Sludge Profile Control (OSPC). Fifth, ground process flow of oily sludge for profile control was designed.
The following conclusion can be drawn from the study: OSPC is a Reutilization Technology for oily sludge, which could seal up oily sludge in-situ in oil reservoir and be favorable for increasing production of oil wells through profile control. Through the rheology and plugging test, it was clear that OSPC could greatly reduce the pollution risk of oily sludge and the ground treatment cost, and solid phase and oil phase of mud were retained in the formation. It could plug high permeability channels and high permeability area (the plugging rate was more than 90%) to adjust water/steam injection profile of water/thermal recovery wells. Profile control agent, engineering design method and ground process flow for oily sludge were developed. The technology applied 72 wells in the oilfield, 184 thousand tons of oily sludge were used in total, production of crude oil was increased by 84 thousand barrels, and a lot of sludge treatment costs could be saved.
Despite decades of numerical, analytical and experimental researches, sand production remains a significant operational challenge in petroleum industry. Amongst all techniques, analytical solutions have gained more popularity in industry applications because the numerical analysis is time consuming; computationally demanding and solutions are unstable in many instances. Analytical solutions on the other hand are yet to evolve to represent the rock behaviour more accurately.
We therefore developed a new set of closed-form solutions for poro-elastoplasticity with strain softening behaviour to predict stress-strain distributions around the borehole. A set of hollow cylinder experiments was then conducted under different compression scenarios and 3D X-Ray Computed Tomography was performed to analyse the internal structural damage. The results of the proposed analytical solutions were compared with the experimental results and good agreement between the model prediction and experimental data was observed. The model performance was then tested by analysing the onset of sand production in a well drilled in Bohai Bay in Northeast of China. Acoustic and density log along with core data were used to provide the input parameters for the proposed analytical model in order to predict the potential sanding in this well. The proposed solution predicted the development of a significant plastic zone thus confirming sand production observed by today sanding issue in this well.
Yang, Jun (University of Regina) | Wang, Xiangzeng (Shaanxi Yanchang Petroleum Group, Xi'an) | Wang, Shubao (Shaanxi Yanchang Petroleum Group, Xi'an) | Gao, Ruimin (Shaanxi Yanchang Petroleum Group, Xi'an) | Zhang, Yizhong (University of Regina) | Yang, Yongchao (Shaanxi Yanchang Petroleum Group, Xi'an) | Zeng, Fanhua (University of Regina)
Air-foam flooding has already been pilot-tested and approved as a feasible and promising EOR method in tight oil reservoir. This study is to develop a simple but effective model to predict dynamic performance of air-foam flooding by considering main physical and chemical mechanisms in this process, such as gas channeling caused by mobility difference, flue gas driving and instability of foam.
According to the instability of foam, a new model is proposed to estimate recovery factor, which separates foam flooding status into three areas, including gas, water and foam area. Prediction of breakthrough time is critical for this model, which is estimated according to relation between area being swept and area to be swept by cycle of injected slug. Once the breakthrough time of gas and surfactant solution are estimated, dynamic performance of every stage during air-foam flooding is predictable. Relation between recovery factor and production time or PV can be predicted, if essential reservoir, fluid and operational parameters are provided.
Relative numerical simulation studies on homogeneous case and heterogeneous case are both introduced to validate proposed model. Results of comparison suggest this model is highly consistent with the numerical simulation results. The most extreme difference in recovery factor after ten years between proposed method and simulation is less than 6.2%, which is less than 2.5% in most case. Meanwhile, this model requires much less input data than numerical simulation for dynamic performance prediction, which makes it a really convenient tool to evaluate potential of an air-foam flooding project. Sensitivity analysis is introduced to study effects of variation in parameters on the performance of air-foam flooding project, including fluid injection rate, slug size, slug proportion and reservoir heterogeneity. The higher liquid ratio is injected in each slug, the better recovery factor is obtained. However, there isn't much difference once liquid ratio is higher than 50%. Recovery factor increases with higher fluid injection rate. Meanwhile, the increasing rate of recovery factor drops as fluid injection rate increases. Also, optimum slug size exists which means any slug size being higher or lower this value would result in lower recovery factor. These conclusions can help get optimized operational parameters once economic data are settled.
This proposed model considered major mechanisms in air-foam flooding and related reservoir, fluid and operational parameters, and provided a fast approach to predict dynamic performance of air-foam flooding and can be used as a tool to optimize the operational parameters. The core idea of this method, such as the estimation of breakthrough time, also provides a new approach to estimate the performance of other immiscible flooding method.
Wang, G. (SINOPEC Research Institute of Petroleum Engineering) | Zhou, H. (SINOPEC Research Institute of Petroleum Engineering) | Fan, H. (SINOPEC Research Institute of Petroleum Engineering) | Si, N. (SINOPEC Research Institute of Petroleum Engineering) | Liu, J. (SINOPEC Research Institute of Petroleum Engineering) | Ma, D. (SINOPEC Research Institute of Petroleum Engineering) | Pang, W. (SINOPEC Research Institute of Petroleum Engineering)
The SINOPEC Fuling shale gas field is the first large-scale commercial development shale gas field of China, which have been built as a productivity of 5 billion shale gas field until 2015. The problems faced in this location is narrow margin between pore (or collapse)and fracture pressure, therefore the mud loss, collapsing and gas kick are very common problem encountered while drilling, the ROP decreases greatly and the cost of drilling operation increases rapidly. With falling oil and natural gas prices, greater efficiency and excellence in well construction is called for, the MPD related theoretical model and successful use of MPD techniques for improving ROP, controlling gas kick and mud loss, reducing drilling cost for the shale gas horizontal well drilling in Fuling is described.
Firstly, a new utility gas kick detect method based on real-time WHP analysis through the theoretical and model analysis was established, in which the WHP variation caused by the tripping, ROP and flow rate variation were taken into account, through which the gas kick can accurately detected as soon as quickly. Secondly, for improving the pressure control precision, a three-layer feedback control method was established and programmed in the controller, through which the bottom hole pressure (BHP) can be adjusted very stable. Moreover, integrated software that combined MPD design and gas kick control simulation was developed based on which the best pressure control procedure and kick initial response can be obtained easily.
The MPD technique has been applied in several wells in Fuling shale gas field of SINOPEC, based on the integrated software, the BHP, flow rate, WHP, mud density, and others drilling parameters were all obtained. And through MPD, the drilling results show that the ROP of there wells were improved about 13.9-82%, the outage time have reduced more than 60%. Moreover, through using the low-density drilling mud, the mud loss has been successfully prevented, and also reduced the mud cost.
This study will presented the utility theoretical model for MPD gas kick detection, three-layer feedback pressure control method, and the MPD application in shale gas drilling. Through the application of the MPD, the results show that the ROP in shale gas horizontal well drilling has been improved obviously, the optimal oil based drilling mud density was designed has successfully prevented the mud loss and reduced the drilling cost.
We have witnessed great progress of reservoir geophysics in China in recent years. One particular highlight is the 3.5D time lapse technology. With this technological advancement existing 3D seismic data can be effectively integrated with real time dynamic production data to predict water coning, by-passed oils, and other changes in reservoirs in a mature oil field. Case studies will be shown in the presentation.
Presentation Date: Monday, October 17, 2016
Start Time: 1:50:00 PM
Presentation Type: ORAL
Indicator ratios of the concentrations of polycyclic aromatic hydrocarbons (PAH) are wide used to determine the sources of the hydrocarbon pollutions. These estimations are used for identification of sources of PAH itself as well as of the pollutions that satellites they are (products of every combustion processes and oil pollutions). The necessity of assessments is connected with the problems of identification of the causes of the environmental damages as a result of pollution of the environments. The indicator ratios of PAH are considered as a “geochemical markers” that are used to determine the sources of the pollutants. This research is based on the multiple literature data about the PAH concentrations in natural and man-made objects. The main purpose of this research is to analyze the accuracy of the received assessments and the assessment of the possibility to use the identified of the foreign researches. Critical values of the indicator ratios in the natural conditions Russian oil and gas industry.
The results of the research allow to select the geochemical markers, mostly “sensitive” to the pollution character, indicator ratios of the concentrations of polycyclic aromatic hydrocarbons (PAH). These chemicals affects the environment with the combustion processes or together with the oil (oil product) pollution. As a result is possible the identification of the causes of the environmental damages depending on the pollution composition of the time of the pollutant emission.
The research allowed to determine and to construct the set of the most informative geochemical indicators (markers) to use in the climatic and landscape conditions of Russia for the various technogenic objects. Despite the practically half-century history of use of the indicator ratios based on PAH concentrations, in Russia such assessments are not widely used. The causes are set of complicating factors hindering the implementation of indicators developed abroad, unadjusted for domestic natural conditions. It is necessary to adjust the ratios due to the different methods of extraction of PAHs from various substances (materials burned or released to the environment during the oil spills), the technology used, climatic conditions, types of pollution.
The paper presents new data on the information content of indicators for various polluted environments and suggestions for their uses in the identification of sources of PAHs in order to identify the causes of hydrocarbon contamination.
Ezekiel, Justin (China University of Petroleum) | Wang, Yuting (China University of Petroleum) | Liu, Yanmin (China University of Petroleum) | Zhang, Liang (China University of Petroleum) | Deng, Junyu (China University of Petroleum) | Ren, Shaoran (China University of Petroleum)
This paper provides a comprehensive overview on the oxidation reactions and improved oil recovery (IOR) processes of air injection into low permeability light oil reservoir based on detailed analysis of some field projects and reservoir simulation case study carried out on a largely dipping, low permeability light oil reservoir, the Q131 oil block located in Eastern China to analyze the characteristics and processes of air injection. Kinetic models of low temperature oxidation (LTO) reactions were designed and used in the reservoir simulation study to predict oxygen consumption in the reservoir, examine the reaction schemes, IOR mechanisms, and the thermal effect of oxidation reactions occurring during the air injection process. The results of the study including temperature effects, oxygen concentration, oil saturation, gas breakthrough, GOR, and cumulative oil produced were outlined and discussed in details.
Gas condensate has become very important because the liquid makes it a high-quality hydrocarbon fluid. Tight gas condensate reservoirs may contain large reserves, but can be extremely costly to develop. The Baimiao gas condensate reservoir is a deep, structurally complex, low- permeability play with a high condensate yield.
This kind of tight gas condensate reservoir encounters many challenges in its exploitation, especially well bottom-hole liquid dropout. Many of the producing wells in the Baimiao tight gas field do not naturally produce the liquids that dropout in-situ around the wellbore. Thus, it is imperative that innovative and effective technologies are applied to lift the condensate-collecting bottom-hole, ultimately prolonging the life of the well and improving the reservoir gas recovery. The techniques used include liquid drainage with narrow tubing, a newly designed plunger gas-lift with a skid-mounted gas-lift, and an interstitial gas-lift.
During the last five years, the Baimiao operator team used integrated gas-lift technology and fine operating procedures to produce the gas condensate. The primary objective of this paper is to advance the understanding of multiphase flow production within tight gas condensate reservoirs. To achieve the objective, a series of closed-gas-lift techniques for field application were introduced; the results from the application of the techniques are presented. Field example summaries are presented at the end of the paper.