Study on the Environmental Impact of Oil and Gas Field Development on the Ecological Red Line Area

To cooperate with the five ministries and commissions of the state to carry out joint investigation on the environmentally sensitive areas involved in oil and gas exploration and development,for the problems found in survey,containing complex type and numerous amount of ecologically sensitive space and ecological red line involved in oil and gas field enterprises,scientific nature of delimitation,lack of strong support of laws and regulations for forced withdrawal of oil and gas production facilities in these areas,some countermeasures and suggestions were proposed,such as further evaluating and combing scope and functional zoning of existing environmentally sensitive areas and ecological red lines,treating differently,enhancing pertinence of prohibition in ecologically sensitive regions,declining blindness of the withdrawal of oil and gas facilities in environmentally sensitive areas,strengthening seriousness of approval of exploration and mining rights of oil and gas resources,and establishing strategic reserve exploration and hierarchical development mechanism. Moreover,oil and gas field enterprises should integrate more efforts to ① accelerate to find out the current situation of environmental quality,② adhere to developing in protection,and protecting in development,③ increase attention and participation strengthen of providing technical support for national oil and gas exploration and development strategy evaluation,④ accelerate communication and docking with local governments on the ecological red line,⑤ actively strive to be included in the positive list management of local governments,⑥ accelerate to establish and perfect primary database of oil and gas production and facilities construction,and ⑦ document management information system of the ecological red line.

Technological progress and development directions of PetroChina overseas oil and gas field production

This study reviews the development history of PetroChina’s overseas oil and gas field development technologies, summarizes the characteristic technologies developed, and puts forward the development goals and technological development directions of overseas business to overcome the challenges met in overseas oil and gas production. In the course of PetroChina’s overseas oil and gas field production practice of more than 20 years, a series of characteristic technologies suitable for overseas oil and gas fields have been created by combining the domestic mature oil and gas field production technologies with the features of overseas oil and gas reservoirs, represented by the technology for high-speed development and stabilizing oil production and controlling water rise for overseas sandstone oilfields, high efficiency development technology for large carbonate oil and gas reservoirs and foamy oil depletion development technology in use of horizontal wells for extra-heavy oil reservoirs. Based on in-depth analysis of the challenges faced by overseas oil and gas development and technological requirements, combined with the development trends of oil and gas development technologies in China and abroad, overseas oil and gas development technologies in the future are put forward, including artificial intelligence reservoir prediction and 3 D geological modeling, secondary development and enhanced oil recovery(EOR) of overseas sandstone oilfields after high speed development, water and gas injection to improve oil recovery in overseas carbonate oil and gas reservoirs, economic and effective development of overseas unconventional oil and gas reservoirs, efficient development of marine deep-water oil and gas reservoirs. The following goals are expected to be achieved: keep the enhanced oil recovery(EOR) technology for high water-cut sandstone oilfield at international advanced level, and make the development technology for carbonate oil and gas reservoirs reach the international advanced level, and the development technologies for unconventional and marine deep-water oil and gas reservoirs catch up the level of international leading oil companies quickly.

Development characteristics, models and strategies for overseas oil and gas fields

Based on about 20 years of accumulated experience and knowledge of oil and gas field development in overseas countries and regions for China's oil companies, the development features, ideas, models and plan designing strategies of overseas oil and gas fields were comprehensively summarized. Overseas oil and gas field development has ten major features, such as non-identity project resource, diversity of contract type, complexity of cooperation model, and so on. The overseas oil and gas field development aims at the maximization of production and benefit during the limited contract period, so the overseas oil and gas field development models are established as giving priority to production by natural energy, building large-scale production capacity, putting into production as soon as possible, realizing high oil production recovery rate, and achieving rapid payback period of investment. According to the overseas contract mode, a set of strategies for overseas oil and gas field development plans were made. For tax systems contracts, the strategy is to adopt the mode of "first fat and then thinner, easier in the first and then harder", that is, early investment pace, production increase rate, development workload and production were decided by the change of tax stipulated in the contract. For production share contracts, the strategy is to give priority to high production with a few wells at a high production recovery rate to increase the cost-oil and shorten the period of payback. For technical service contracts, the strategy is that the optimal production target and workload of the project were determined by the return on investment, so as to ensure that the peak production and stable production periods meet the contract requirements.

CNPC Beefs up Cooperative Development for Onshore Oil and Gas Fields

ＣＮＰＣＢｅｅｆｓｕｐＣｏｏｐｅｒａｔｉｖｅＤｅｖｅｌｏｐｍｅｎｔｆｏｒＯｎｓｈｏｒｅＯｉｌａｎｄＧａｓＦｉｅｌｄｓＣｕｉＹａｏｎａｎ，（ＶｉｃｅＣｈｉｅｆＥｎｇｉｎｅｅｒｏｆＩｎｔｅｒｎａｔｉｏｎａｌＥｘｐｌｏｒａｔｉｏｎａｎｄＤｅｖｅｌｏｐｍｅｎ...

Reservoir accumulation conditions and key exploration&development technologies for Keshen gas field in Tarim Basin

The Keshen gas field is located in the central part of Kuqa foreland thrust belt in Tarim Basin,and is another large gas field discovered in Kuqa depression after Kela 2 gas field.Since the breakthrough in 2008,a number of large and medium scale gas reservoirs including Keshen 2,Keshen 5 and Keshen 8 have been discovered,that are characterized by ultra depth,ultra-high pressure,ultra-low porosity,ultra-low permeability,high temperature and high pressure.With natural gas geological reserves of nearly trillion cubic meters and production capacity of nearly 5.5 billion cubic meters,the Keshen gas field is the main natural gas producing area in Tarim Oilfield.The Keshen gas field is located in a series of thrusting imbrication structures in the Kelasu structural belt of Kuqa foreland thrust belt.The salt roof structure,plastic rheology of salt beds and pre-salt faulted anticlinal structure constitute the large wedge-shaped thrust body.The thick delta sandstone of the Cretaceous Bashijike Formation is widely distributed,and it forms the superior reservoir-caprock combination with overlying Paleogene thick gypsum-salt bed.The deep Jurassic-Triassic oil and gas migrate vertically along fault system formed in Late Himalaya,break through the thick Cretaceous mudstone and move laterally along the fracture system of the pre-salt reservoirs,to form anticline and fault anticline high pressure reservoir groups.Through near ten years of studies,the three-dimensional seismic acquisition and processing technology for complex mountainous areas,extrusion salt-related structural modeling technology and fractured low-porosity sandstone reservoir evaluation technology have been established,which lay a foundation for realization of oil and gas exploration objectives.Logging acquisition and evaluation technology for high temperature,high pressure,ultra-deep and low-porosity sandstone gas reservoirs,and efficient development technology for fractured tight sandstone gas reservoirs have been developed,which provide a technical support for efficient exploration&development and rapid production of the Keshen gas field.

Prediction of wax precipitation region in wellbore during deep water oil well testing

During deep water oil well testing, the low temperature environment is easy to cause wax precipitation, which affects the normal operation of the test and increases operating costs and risks. Therefore, a numerical method for predicting the wax precipitation region in oil strings was proposed based on the temperature and pressure fields of deep water test string and the wax precipitation calculation model. And the factors affecting the wax precipitation region were analyzed. The results show that: the wax precipitation region decreases with the increase of production rate, and increases with the decrease of geothermal gradient, increase of water depth and drop of water-cut of produced fluid, and increases slightly with the increase of formation pressure. Due to the effect of temperature and pressure fields, wax precipitation region is large in test strings at the beginning of well production. Wax precipitation region gradually increases with the increase of shut-in time. These conclusions can guide wax prevention during the testing of deep water oil well, to ensure the success of the test.

模糊数学在优选油田开发方案中的应用

针对油气田开发方案中各评价指标既互相依赖 ,又互相矛盾 ,难以进行全面评价的特点。使用模糊数学方法建立计算模型 ,通过模糊综合评判 。

水驱油田的驱替特征与递减特征

推导了Ａｒｐｓ递减指数ｎ＝０，即指数递减对应的水驱特征曲线表达式。与ｎ＝０．５和１．０的递减曲线，即ｎ＝０．５的双曲递减和调和递减对应的水驱特征曲线一起，首次建立了完整的递减曲线与水驱曲线的联系。利用含水率（ｆｗ）～可采储量采出程度（Ｒ）关系图上的递减指数ｎ＝０、０．５、１．０的理论曲线，研究了水驱油田的驱替特征与递减特征。研究表明，我国绝大多数层状油田的ｆｗ～Ｒ关系在ｎ＝０到１．０的理论曲线范围内；底水驱灰岩油田有不同于层状油田的特别的ｆｗ～Ｒ关系；油田开采方式决定了ｆｗ～Ｒ变化的大的趋势；油水粘度比和油层非均质性对ｆｗ～Ｒ关系有很大影响，油水粘度比越大，油层非均质性越强，则ｆｗ～Ｒ曲线越凸。油田开发后期，实际油田的ｆｗ～Ｒ关系均趋向于ｎ＝０．５的曲线。

油气田开发方案优选方法的研究

本文建立了一类优选油气田开发方案的模糊积分评价与灰色局势决策方法。全面地考虑了各种技术、经济指标在整个方案优劣评价中的重要程度,对权重的确定进行了改进,并把所建立的方法应用于某气藏开发方案的优选中。两种方法所得结论均与实际一致,说明灰色系统理论与模糊积分方法都可成功地应用于油气田开发方案的经济评价中。

茨13块稠油油藏注稠化水开发数值模拟研究

方法利用数值模拟技术，研究茨１３块稠油油藏注稠化水开发方法。目的优选注稠化水方案，提高茨１３块开发效果。结果稠化水驱不宜注入较高浓度的稠化水，而且应避射底水，其效果优于水驱。经济评价认为，方案六和方案七为最优方案，先实施方案六，见效后，再实施方案七；方案实施中，应注意油层解堵、配产、配注等问题。结论稠化水驱可以提高稠油油藏的采出程度，增加产油量；

基于层次分析法的油田开发方案优选

油田开发方案的优化是油田开发设计的一个重要环节,同时也是一个多目标决策过程。在分析油田开发方案影响因素的基础上,选取5个反映了油田开发方案的经济和技术的评价指标(原油采收率、总投资、生产速度、年递减率和动态投资回收期),应用层次分析法(AHP)基本原理对5种不同油田开发方案进行综合评价,得出最优油田开发方案。油田开发方案优选结果表明,该方法具有较强的可操作性和广泛的适用性。

基于灰色关联理想解法的油气田开发方案

对于油田开发方案进行选择是一项非常重要、且比较复杂的工程。以灰色系统理论为依据的关联分析原理则是一种较为有效的对油田开发方案进行选择的一种分析方法。本文将就基于灰色关联理想解法的油气田开发方案进行一定的分析与探讨。

惠州油田的开发与浮式生产系统

惠州21—1油田位于我国南海。该海域水深,海况条件恶劣,油田属于边际油田,因此,按常规的工程方案开发,投资大、经济效益差。惠州21—1油田采用'井口平台+生产储油装置'的工程开发方案,系泊系统采用'可解脱的浮筒式转台系泊系统(BTM)',因而降低了开发投资。在惠州21—1油田工程设计阶段又兼顾到新发现的惠州26—1油田的联合开发问题。充分地利用现有浮式生产系统及生产设施、设备和气资源的潜力,有效地降低了两个油田的开发投资。