大王北油田大37块开发效果评价及潜力研究
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摘要
我国投入开发的低渗透油田的储量，占总动用储量的比例越来越大，这些油田中的相当部分处于低产低效状态，而未动用石油地质储量中，低渗透油田储量占的比例更大，已开发的低渗透油田如何进一步改善开发效果，未动用的低渗透油田储量如何尽快有效地投入开发，这对石油开发的持续稳定发展，有着十分重要的意义。
大王北油田是一个低渗透油田，大37块是该油田的一个主力区块，该块含油面积17.7km~2，探明石油地质储量1738×10~4t。十多年的开发历史清楚地显示该油藏具有储层非均质严重、渗透率低、天然能量不足、产能低等特点。通过对大37块油田地质研究(包括构造、储层及沉积特征)和油藏开采特征研究(包括油井产能、区块递减、含水变化规律及层间矛盾)，全面评价了大37块的开发效果。揭示了油层层数多、含油井段长、油水井多层合采合注所带来的严重层间干扰。分析了不同驱动条件下的采收率；运用相渗曲线推导出理论含水与采出程度关系曲线；运用产量递减规律、含水上升规律等对稳产态势进行分析；对油田开发效果进行评价。分析了目前开发方式对注水开发效果及储量动用差异大产生的不足。
通过油田开发现状及开发效果进行的综合评价，对该块的挖潜方向进行了论证。针对低渗透油藏开发中存在的主要矛盾，采取切实有效的对策，以改善其开发效果，提高采收率。通过开展精细油藏描述工作，加强精细地质研究，搞好储层评价，研究砂体展布规律及井网适应性。开展缩小井距开发先导试验，通过适当加密井网，建立有效生产压差，改善开发效果。低渗透油藏的主要特征是：储层物性差、渗透率低，油水赖以流动的通道细小，流体的渗流阻力很大，液-固界面和液-液界面的相互作用力比较显著。因而低渗透储层的流体，在低压力梯度下，呈低速非线性渗流状态；且渗透率越低，启动压力梯度越大，压力传导速度越慢。在油田开发中主要体现在能量利用率低，产量下降快，水井吸水能力差，注水井周围憋压高，采油井见效慢，很大一部分驱动压力用在克服启动压力梯度上。为此通过对现注采井网适应性、井网密度与最终采收率的关系、经济极限井网密度等研究，提出井网加密建议。并按其重要性将增产机理划分为：(1)改善油层的连续性；(2)改善平面扫油效率；(3)改善垂向扫油效率；(4)开采尖灭带的原油；(5)改善经济界限。
总之，通过对该块构造、储层、开发效果及剩余油分布等方面研究，对开发中存在的主要问题有了清楚的认识，研究了该块井网加密的必要性和可行性，制定了大37块改善开发效果的具体措施，为提高低渗透油田开发效果进行了深入的研究和有益的尝试。
In China, the rate of reserves of the low permeability oilfield gets more and more large in the total producing reserves. In these oilfields, considerable portion keeps the state of low production and low efficiency among them. This rate gets larger in the proven reserves petroleum-in-place. Then how to further improve the development effect for the developed low permeability oil field and hoe to develop rapidly and effectively for the proven reserves low permeabi1ity oilfield are very significant for the continued and steady development of the petroleum development.
DaWang Bei oil field is a low permeability oilfield, and Da 37 block is a main block of this oil field. The oil-bearing area is 17.7 km2 and the proved reserves is
1738×104t. The course of ten years' development shows clearly that the oil reservoir is characteristic of the severe heterogeneous reservoir the low permeability, the shortage of natural energy and low productivity. On the basis of researching the geology of Da 37 block (concluding structure, reservoir and deposit features) and reservoir production characteristic (concluding productivity of oil well, block lapse, water-filled changing regulation and interlayer contradictory), the thesis wholly evaluates the development effect of Da 37 block, announces the heavy interlayer interference which the large number of oil layers, long oil-bearing interval many layers cooperative exploitation and cooperative water injection cause. At the same time, it analyzes the recovery efficiency under the condition of different driving, deduces the relation curve of theoretical water-bearing to recovery percent of reserves by utilizing phase permeability curves, analyzes the production rate-maintenance situation by applying the law of production declining and water-bearing rising and appraises the development effect of the oil field.
By synthetically evaluating the development effect and current status, the thesis demonstrates the direction of excavating latent capacity. In the light of the main contradictory which exists during developing the low permeability reservoir, we adopt the effective countermeasure in order to improve the development effect and recovery efficiency. By carrying out fine reservoir descriptions, strengthening fine geology studies and reservoir evaluation, the thesis researches the law of sand distribution and well network adaptability. To make the development effect better, we reduce well spacing to develop the precursor experiment, infill well network appropriately, build effective producing pressure drop. The main characteristics of low permeable reservoir are as follows: bad reservoir physical property, low permeability, narrow channel which oil and water pass by, very strong percolation flow resistance force, the notable interaction force between liquid-solid interface and liquid-liquid interface. So the fluid of low permeable reservoir appears the percolation flow state of low speed and nonlinearity. And the same time the lower permeability is the greater starting pressure gradient and the more slow speed of pressure conduction is. In oil field development, this reflects mainly: low
energy utilization ratio, rapid productivity drop, poor water-intake capacity, high hit pressure around the water input well, slow becoming effectively of producing well and a great part of driving pressure is used to overcome the pressure gradient. So by researching injection-production pattern adaptabi 1 i ty, relationship of well network density and ultimate recovery and well network density of economic limit, it brings out the suggestion of encrypting well network and according to the significance, divides the increasing production theories into: 1) improving the oil-bearing formation continuity; 2) improving the oil scavenge efficiency of plane and vertical plane; 3) developing the oil in pinching belt; 4) improving the economic limit.
fn a word, by researching the structure , reservoir, development effect and remaining oil distribution, we have a clear recognition to the main probl
大王北油田是一个低渗透油田，大37块是该油田的一个主力区块，该块含油面积17.7km~2，探明石油地质储量1738×10~4t。十多年的开发历史清楚地显示该油藏具有储层非均质严重、渗透率低、天然能量不足、产能低等特点。通过对大37块油田地质研究(包括构造、储层及沉积特征)和油藏开采特征研究(包括油井产能、区块递减、含水变化规律及层间矛盾)，全面评价了大37块的开发效果。揭示了油层层数多、含油井段长、油水井多层合采合注所带来的严重层间干扰。分析了不同驱动条件下的采收率；运用相渗曲线推导出理论含水与采出程度关系曲线；运用产量递减规律、含水上升规律等对稳产态势进行分析；对油田开发效果进行评价。分析了目前开发方式对注水开发效果及储量动用差异大产生的不足。
通过油田开发现状及开发效果进行的综合评价，对该块的挖潜方向进行了论证。针对低渗透油藏开发中存在的主要矛盾，采取切实有效的对策，以改善其开发效果，提高采收率。通过开展精细油藏描述工作，加强精细地质研究，搞好储层评价，研究砂体展布规律及井网适应性。开展缩小井距开发先导试验，通过适当加密井网，建立有效生产压差，改善开发效果。低渗透油藏的主要特征是：储层物性差、渗透率低，油水赖以流动的通道细小，流体的渗流阻力很大，液-固界面和液-液界面的相互作用力比较显著。因而低渗透储层的流体，在低压力梯度下，呈低速非线性渗流状态；且渗透率越低，启动压力梯度越大，压力传导速度越慢。在油田开发中主要体现在能量利用率低，产量下降快，水井吸水能力差，注水井周围憋压高，采油井见效慢，很大一部分驱动压力用在克服启动压力梯度上。为此通过对现注采井网适应性、井网密度与最终采收率的关系、经济极限井网密度等研究，提出井网加密建议。并按其重要性将增产机理划分为：(1)改善油层的连续性；(2)改善平面扫油效率；(3)改善垂向扫油效率；(4)开采尖灭带的原油；(5)改善经济界限。
总之，通过对该块构造、储层、开发效果及剩余油分布等方面研究，对开发中存在的主要问题有了清楚的认识，研究了该块井网加密的必要性和可行性，制定了大37块改善开发效果的具体措施，为提高低渗透油田开发效果进行了深入的研究和有益的尝试。
In China, the rate of reserves of the low permeability oilfield gets more and more large in the total producing reserves. In these oilfields, considerable portion keeps the state of low production and low efficiency among them. This rate gets larger in the proven reserves petroleum-in-place. Then how to further improve the development effect for the developed low permeability oil field and hoe to develop rapidly and effectively for the proven reserves low permeabi1ity oilfield are very significant for the continued and steady development of the petroleum development.
DaWang Bei oil field is a low permeability oilfield, and Da 37 block is a main block of this oil field. The oil-bearing area is 17.7 km2 and the proved reserves is
1738×104t. The course of ten years' development shows clearly that the oil reservoir is characteristic of the severe heterogeneous reservoir the low permeability, the shortage of natural energy and low productivity. On the basis of researching the geology of Da 37 block (concluding structure, reservoir and deposit features) and reservoir production characteristic (concluding productivity of oil well, block lapse, water-filled changing regulation and interlayer contradictory), the thesis wholly evaluates the development effect of Da 37 block, announces the heavy interlayer interference which the large number of oil layers, long oil-bearing interval many layers cooperative exploitation and cooperative water injection cause. At the same time, it analyzes the recovery efficiency under the condition of different driving, deduces the relation curve of theoretical water-bearing to recovery percent of reserves by utilizing phase permeability curves, analyzes the production rate-maintenance situation by applying the law of production declining and water-bearing rising and appraises the development effect of the oil field.
By synthetically evaluating the development effect and current status, the thesis demonstrates the direction of excavating latent capacity. In the light of the main contradictory which exists during developing the low permeability reservoir, we adopt the effective countermeasure in order to improve the development effect and recovery efficiency. By carrying out fine reservoir descriptions, strengthening fine geology studies and reservoir evaluation, the thesis researches the law of sand distribution and well network adaptability. To make the development effect better, we reduce well spacing to develop the precursor experiment, infill well network appropriately, build effective producing pressure drop. The main characteristics of low permeable reservoir are as follows: bad reservoir physical property, low permeability, narrow channel which oil and water pass by, very strong percolation flow resistance force, the notable interaction force between liquid-solid interface and liquid-liquid interface. So the fluid of low permeable reservoir appears the percolation flow state of low speed and nonlinearity. And the same time the lower permeability is the greater starting pressure gradient and the more slow speed of pressure conduction is. In oil field development, this reflects mainly: low
energy utilization ratio, rapid productivity drop, poor water-intake capacity, high hit pressure around the water input well, slow becoming effectively of producing well and a great part of driving pressure is used to overcome the pressure gradient. So by researching injection-production pattern adaptabi 1 i ty, relationship of well network density and ultimate recovery and well network density of economic limit, it brings out the suggestion of encrypting well network and according to the significance, divides the increasing production theories into: 1) improving the oil-bearing formation continuity; 2) improving the oil scavenge efficiency of plane and vertical plane; 3) developing the oil in pinching belt; 4) improving the economic limit.
fn a word, by researching the structure , reservoir, development effect and remaining oil distribution, we have a clear recognition to the main probl
引文
1 包怀庆主编．马西深层层状低渗透砂岩油藏．北京：石油工业出版社，1996
2 钟显彪主编．红岗萨尔图层低渗透砂岩油藏．北京：石油工业出版社，1997
3 李道品主编．低渗透砂岩油田开发．北京：石油工业出版社，1997
4 罗蛰潭主编．油层物理．地质出版社，1984
5 邱光东主编．老君庙M层低渗透砂岩油藏．北京：石油工业出版社，1998
6 郎兆新主编．油藏工程基础．石油大学出版社，1991
7 李兴国主编．陆相储层沉积微与微构造．北京：北京：石油工业出版社，2000
8 裘怿南，刘雨芬等．低渗透砂岩油藏开发模式．北京：石油工业出版社，1998
9．彭仕密、黄述旺，油藏开发地质学，石油工业出版社，1998年。
10．张一伟等，陆相油藏描述，北京：石油工业出版社，1997年。
11．赵彦超等，油藏描述技术，中国地质大学出版社，1994年。
12．王秉海等，胜利油区地质研究与勘探实践，石油大学出版社，1992年。
13．刘泽容、信荃麟等，油藏描述原理与方法技术，石油工业出版社，1993年。
14．曾文冲，油气藏储集层评价技术，石油工业出版社，1991年。
15．熊琦华、吴胜和、彭仕密，储层地质学，石油工业出版社，1994年。
16．陈永生，油田非均质对策论，石油工业出版社，1993年。
17．杜贤樾等，胜利油区勘探开发论文集，地质出版社，1997年。
18．洪世铎，油藏物理基础，石油工业出版社，1991年。
19．张建国，油气层渗流力学，石油工业出版社，1994年。
20．J．W．KRAMERS等著，刘建华译，储层特征描述中的多学科研究，国外石油地质，1990年第期。
21．冈秦麟，高含水期油田改善水驱效果新技术，石油工业出版社，1999年。
22. O. Robert A. James, Causes of permeability variation in a Lower Cretaceous reservoir unit in the West Siberiar Basin, Russia, Marine and Petroleum Geology, Vol. 13, No. 4, pp. 393-406, 1996。
2 钟显彪主编．红岗萨尔图层低渗透砂岩油藏．北京：石油工业出版社，1997
3 李道品主编．低渗透砂岩油田开发．北京：石油工业出版社，1997
4 罗蛰潭主编．油层物理．地质出版社，1984
5 邱光东主编．老君庙M层低渗透砂岩油藏．北京：石油工业出版社，1998
6 郎兆新主编．油藏工程基础．石油大学出版社，1991
7 李兴国主编．陆相储层沉积微与微构造．北京：北京：石油工业出版社，2000
8 裘怿南，刘雨芬等．低渗透砂岩油藏开发模式．北京：石油工业出版社，1998
9．彭仕密、黄述旺，油藏开发地质学，石油工业出版社，1998年。
10．张一伟等，陆相油藏描述，北京：石油工业出版社，1997年。
11．赵彦超等，油藏描述技术，中国地质大学出版社，1994年。
12．王秉海等，胜利油区地质研究与勘探实践，石油大学出版社，1992年。
13．刘泽容、信荃麟等，油藏描述原理与方法技术，石油工业出版社，1993年。
14．曾文冲，油气藏储集层评价技术，石油工业出版社，1991年。
15．熊琦华、吴胜和、彭仕密，储层地质学，石油工业出版社，1994年。
16．陈永生，油田非均质对策论，石油工业出版社，1993年。
17．杜贤樾等，胜利油区勘探开发论文集，地质出版社，1997年。
18．洪世铎，油藏物理基础，石油工业出版社，1991年。
19．张建国，油气层渗流力学，石油工业出版社，1994年。
20．J．W．KRAMERS等著，刘建华译，储层特征描述中的多学科研究，国外石油地质，1990年第期。
21．冈秦麟，高含水期油田改善水驱效果新技术，石油工业出版社，1999年。
22. O. Robert A. James, Causes of permeability variation in a Lower Cretaceous reservoir unit in the West Siberiar Basin, Russia, Marine and Petroleum Geology, Vol. 13, No. 4, pp. 393-406, 1996。