阿姆河右岸奥贾尔雷气田气井生产异常压力产生原因及对策  

Origins of and countermeasures for the abnormal pressures in well production of the Ojarly gas field in the Right Bank of the Amu-Darya River, Turkmenistan

作　　者：张培军 高仪君 万翠蓉[3] 刘荣和 张李 李洪玺 

机构地区：[1]中国石油(土库曼斯坦)阿姆河天然气公司 [2]中国石油川庆钻探工程公司地质勘探开发研究院 [3]中国石油西南油气田公司重庆气矿

出　　处：《天然气工业》2016年第10期77-84,共8页Natural Gas Industry

基　　金：中国石油天然气集团公司科学研究与技术开发项目"土库曼斯坦阿姆河右岸上产165亿立方米天然气开发关键技术研究与应用"(编号:2011E-2505);国家科技重大专项"阿姆河右岸中区天然气开发示范工程"(编号:2011ZX05059)

摘　　要：土库曼斯坦奥贾尔雷气田是阿姆河右岸二期工程的主供气田,具有典型的"金豆子"特征:储层物性好、产气能力高。然而,生产过程中却出现了油压连续大幅度下降、与试采方案存在较大差异等异常情况。为此,通过建立气井生产全流程综合分析方法,剖析可能造成气井油压异常变化的3种主要模式,即:(1)模式1——地层能量不足,地层压力下降较快,引起井口压力同步下降;(2)模式2——井筒管流压降异常,生产管柱中可能存在节流效应,造成井筒压降异常增大;(3)模式3——气井生产压差异常增大,产能大幅下降造成井口油压异常下降。在此基础上,通过系统的动态监测和深入地分析,认为该井由于钻井液密度高,而储层孔洞发育,部分重晶石在产层沉淀下来,随着高产量生产,重晶石被带出并在井筒中沉降,致使下部产层被掩埋,产气能力大幅下降,生产油压异常下降。据此及时提出对该井储层再改造、疏通产气通道、增加渗流能力的技术措施,利用连续油管冲砂洗井、酸化改造等措施,降低了综合表皮系数,减小了生产压差,恢复了该井的产气能力,确保了气井高产稳产。Abstract： The Ojarly gas field, the major supplier of the Project Phase II of the Right Bank of the Amu Darya River, is just small but valuable like a golden bean, although it has good reservoir properties and a high gas production capacity, the occurrence of continuous sharp decline of pressure in the well production shows a great difference from the previous well test program. In view of this, an integrated analysis method was established for the whole gas well production process to discover the three main reasons causing the abnormal well pressure. First, the formation energy and pressure dropped so fast that the wellhead pressure also fell over the period. Second, there was abnormal fluids pressure drop in the wellbore tube and throttling effect might occur in the production tube, so the pressure drop be- came abnormally increased. Third, due to the abnormally-increasing gas-yield pressure drop and unusually-decreasing gas productivity, the wellhead oil pressure dropped significantly. Also, through dynamic monitoring and in-depth analysis, it is also considered that due to the high density of drilling fluids and well-developed pores and caverns in the reservoirs, more and more barites separated from the fluids would be settled down covering the pay zones, so both the gas-generating capacity and production pressure significantly decreased. On this basis, some technical countermeasures were taken such as re-stimulation of reservoirs, removal of gas-producing channels, increase of seepage capacity, etc. In addition, by use of sand-flushing and acidizing, both the comprehensive skin factor and the production pres- sure drop were reduced to improve the well gas production capacity and maintain high productivity effectively. This study provides a technical support for long-term sustainable development and production of this gas field.

关 键 词：土库曼斯坦 阿姆河右岸 奥贾尔雷气田 油压异常 全流程综合分析 重晶石沉淀 产层掩埋 冲砂洗井 酸化改造 

分 类 号：TE37[石油与天然气工程—油气田开发工程]