Status of Heavy Oil Development in China

Abstract

Abstract China has significant heavy oil deposit of more than 1.9 billion tons of oil reserve in place (OOIP) with four major heavy oil producing areas, which are Liaohe Oil Field, Xinjiang Oil Field, Shengli Oil Field and Henan Oil Field. China has many types of heavy oil reservoirs such as single-layer, multi-layer, thick-blocked reservoir with wide range of oil viscosity from 100 cp to 100,000 cp and depth from 200m to more than 2000m. Heavy oil has been produced for many years in China. However, the commercial heavy oil development was initial in 1982, when the first cyclic steam injection pilot test was successful in Liaohe Oil Field. In 1993, the heavy oil production had reached 10×106 tons per year. From then on, the annual heavy oil production has kept the level of 10∼13×106 tons for more than 10 years. The development manners of heavy oil reservoir are cyclic steam stimulation (CSS), steamflooding, waterflooding. CSS is the major manner, widely used in traditional-heavy, extra-heavy and super-heavy oil reservoir in China with the annual production more than 85% of total heavy oil production. CSS has become a mature industry technology, which includes high-efficient steam injection, artificial lifting, sand controlling, re-entry drilling, steam surveillance and so on. Steamflooding is successful in developing shallow heavy oil reservoir such as Karamy oil reservoir, including high-temperature profile conformance, surveying and steam measurement technologies. This paper reviews the distribution of heavy oil resources, status of heavy oil development, trends and also the challenges faced in improving utilization of the resources in China. Introduction China has significant heavy oil deposit of more than 1.9 billion tons of oil reserve in place (OOIP) with four major heavy oil producing areas. Heavy oil has been produced for many years in China. However, the commercial heavy oil development was initial in 1982, when the first cyclic steam injection pilot test was successful in Liaohe Oil Field. In 1993, the heavy oil production had reached 10×106 tons per year. From then on, the annual heavy oil production has kept the level for more than 10 years. At present, the oil recovery has reached 18%. The paper will review state-of-the-art of the heavy oil development in China and its technologies and challengs. Resource Base Heavy oil in China is widely distributed and more than 70 fields have been found with more than 1.9 billion tons of oil reserve in place (OOIP). There are 10 main heavy oil areas onshore, which are Daqing, Jilin, Liaohe, Huabei, Dagang, Xinjiang, Tarimu, Tu-hu, Henan, Shengli producing area, among which, the first 8 areas belong to PetroChina Company Limited, the last 2 areas belong to Sinopec Corp. (see Figure 1). In China, heavy oil refers to hydrocarbons having a gas-free viscosity of higher than 100 mPa.s or having a live viscosity higher than 50 mPa.s. According to the oil viscosity, the heavy oil could be divided into sevious types: traditional heavy oil with degassed oil viscosity less than 10,000 mpa.s, super-heavy oil reservoir with degassed oil viscosity from 10,000 to 50,000 mpa.s and extra-heavy oil reservoir with degassed oil viscosity more than 50,000 mpa.s (see Table 1). Heavy oil in China has the characteristics of high resin content, low asphaltene content, low wax content and high viscosity with large variation (see Table 2). The reservoir depth varies greatly from 400m to more than 2500m. In Western China, the heavy oil reservoirs in Karamy are shallow in depth from 200 m to 600 m, and those in Tu-ha area are very deep in depth from 2700 m to 3200 m. In Eastern China, the heavy oil reservoirs in Liaohe area are deep in depth from 600 m to 1200 m.