Abstract:During the“11th Five-Year”, the Jiyang depression has integrally entered into the concealment reservoir exploration stage.Under the conditions of more complex and more concealed exploration targets, and facing more and more difficult exploration situation,the Jiyang depression always maintained a good exploration development situation，and consolidated the resource base for the development of Shengli oilfield. It has important referential significance for further exploration of Shengli oilfield by summarizing exploration features and exploration experience of Jiyang depression in the“11th Five-Year”period. Therefore, through the summary of the distributing characteristics of well types, drilling purposes strata, drilled depth, reservoir types and types of traps that drilled by wells in Jiyang depression in the“11th Five-Year”period，the results showed that the breakthrough from prexploration and risk exploration is important to realize the sustainable development; the upper section of Es4 and the strata above it are still the main exploration target strata system, the Ek and the lower Es4 deep layer have become the reserves focus; the conglomerate reservoir in steep slope, turbidite sand reservoir in the sag slope, beach bar sandstones of gentle slope and the Neogene fluvial sand body such as a lithologic reservoir have upgraded to be the major exploration targets, moreover, the proportion of deep buried hill reservoir also increased significantly as exploration targets. The detailed exploration is the key for a high matured area to obtain progress, and new crucial district to obtain breakthrough. The evaluation of the reservoir and transporting conditions are the main exploration risks for Jiyang depression at present and in the future.

Abstract:The eastern exploration area of Shengli oilfield has fully entered the subtle reservoir exploration stage. We should think strategically and discuss on several dialectical relationship of exploration work. Firstly, we deal with the relationship between the subjective and the objective correctly. That is, we handle correctly the relationship between geological researchers as the subject and the geological body being studied and described as the object. Secondly, we handle relationship between the known and the unknown. We should not stress“absolute”concept, and draw artificially absolute limits, exploration work should follow“cycle, spiral”awareness rules. Thirdly, we handle relationship between technical progress and practical application, and determine that the researchers are the decisive factor, it is the basic principle that we combine with advanced technology and practical application. To think these relationships dialectically, it is conducive to ensure the exploration key of“improving quality and efficiency”. We make positive contribution for oilfield to achieve sustainable development and the successful completion of the task granted by history.

Abstract:The quantitative capacity evaluation of the fault transporting, defined as hydrocarbon resources transported by faults in unit period, has a linear direct ratio relationship with the hydrocarbon resources. The influence factors are expulsion intensity of hydrocarbon, ancient fault throw in reservoir forming period, plane extension length of faults in matured source rock and inactive period of faults. The hydrocarbon exploration potential in west Qingtuozi uplift of Jiyang depression was evaluated by the equation of fault transporting ability. The results show that when the ξ value at 210, there is a very good linear related relationship between total fault transporting capacity and local oil geological reserves in east Xinzhen oilfield (near the research area) and Yonganzhen oil and gas field. According to the fitting results, 18 billion tons of potential oil reserve in Xinlicun oilfield are existed in the Es3 member and Es4 upper section, and need to be located. The Yong101, Yong106, and Yong116 well district in Xinlicun oilfield are the favorable exploration targets, which have favorable hydrocarbon accumulation condition such as adjacent to the source faults, developed trap and abnormal energy-half-time.

Abstract:China’s shale gas exploration and research is still in the primary stage, and facing many complicated geological and engineering problems. Although it has obtained a large number of precious experiences through the analogy of matured shale gas in the United States, it has its unique characteristics. Therefore, it is necessary to establish a set of effective resources evaluation system.Based on the exploration target of shale gas, this paper provides some questions about the different reservoir characteristics at home and abroad, such as the“formation water”storage and percolation mechanism in shale reservoir, the relationship between fracturing effect and genetic types of natural gas, then suggesting the shale reservoir classification evaluation in different depositional system so as to look for the shale gas“dessert”, and realize the reasonable and maintainable development of shale gas in China.

Abstract:The Yonganzhen delta is developed in Minfeng sag and its peripheral area are important oil and gas accumulation belts in Dongying depression, Bohaiwan Basin, China. Based on the principles of seismic sequence, combined with logging and drilling, the target strata of Yonganzhen delta, the middle and the lower submember of third member of Shahejie formation (Es3z-Es3x) are divided into a third-order sequence separately. In the sedimentary stage of Es3z, three fourth-order sequences (MSC1-MSC3) and eight fifth-order sequences (Z1-Z8) are developed; in the sedimentary stage of Es3x, two fourth-order sequences (MSC4-MSC5) and two fifth-order sequences (X1-X2) are developed. Meanwhile, the scales of Yonganzhen deltaic deposition was small in the periods of MSC5-MSC3; in the period of MSC2, the strength of source supply increased from the Qingtuozi salient, the Yonganzhen delta prograded massively, and reached the downthrown block of Shengtuo fault with the depositions of mixed sources; in the period of MSC1, the Yonganzhen delta migrated to the north is affected by the deposition of the Dongying delta. Moreover, the Yonganzhen delta has the characteristic of selfsimilarities for development of sandbody controlled by sequence. The self-similarities illustrate that the delta sandbody is developed within the dropping semi-cycle in each grade of base level cycle, with the sand content higher than that of the rising semi-cycle.

Abstract:The conglomerate reservoir pore structure of the lower Karamay formation in mid and east of 7th block, Karamay oilfield, is fully studied by means of casting thin sections, SEM and petrophysical and mercury injection data. There are three main types of microscopic pore distribution in the conglomerate reservoir of the lower Karamay formation in the study area, the pore diameter distribution is monomodal, bimodal and complex modal. According to nine parameters screened out (porosity, permeability, mean, skewness, the sat?uration median radius, the maximum pore throat radius, the average pore throat radius, as the pore volume ratio and the percentage of non-saturated mercury pore volume), using K-Means clusterting analysis method, the conglomerate reservoir is divided into four major categories of class I, II, III and IV, which are on behalf of the reservoir good, moderate, poor and very poor, then, each type of reservoir pore structure characteristics is summarized. The analysis of the main factors, affecting the pore structure, shows that the factors affecting the pore structure are tectonic, sedimentation and diagenesis. The influence of deposition on the pore structure is mainly characterized by the lithologic control on the physical properties of the reservoir, and for diagenesis on pore structure, mainly by compaction resulting in lower average porosity; and the cementation deteriorates the pore structure and physical properties; meanwhile, the secondary porosity generated by dissolution improves the reservoir pore structure and physical properties; however, the authigenic euhedral crystal mineral by recrystallization filled or partially filled in the intergranular porosity and throat has reduced the porosity by narrower throat and poorer pore connectivity; the pressure solution can generate pressure solution seam, suture, or dissolved pores so as to expand the pore space. The research results provide the basis for the formulation of oil field development decision-making and stimulation.

Abstract:The hydrocarbon-generating potentials of residual ocean basin get more and more attention. Based on the fact that the Junggar basin is underlain by the Precambrian continental block, an upper Paleozoic residual ocean might exist in west Junggar and aast Kazakhstan named the Balkhash-West Junggar residual ocean. Bole-Ebinur Lake sag lies in the south margin of the basin. Many sets of source rocks composed of upper Devonian-lower Carboniferous mudstone, marlstone and biolithite limestone are discovered from Bole-Ebinur Lake sag in southwestern margin of basin. The average TOC of source rocks is 2.19%, and the maximum is 7.11%. And, more close to oil-soaked clastic rocks in Bole-Ebinur Lake sag, the saturated hydrocarbon of source rock extract shows bimodal distribution type with odd-carbon predominance. According to light-to-heavy carbon-number ratios and asphaltenes contents, the upper Paleozoic source rocks well-preserved in the basin are still in a medium mature stage with high hydrocarbon-generating potentials.

Abstract:In this stage, the stratigraphic traps in Jiyang depression is low in success rate of exploratory wells, and pre-drilling risk is difficult to predict. Through the analysis and summary of wells drilled in the“Tenth Five-Year”, the failure of the exploration well is attributed to poor transportation conditions, low filling of oil-gas in reservoir, lack of effective reservoirs and traps, at 49%, 21%, 15% and 15% respectively. The reservoir analysis shows that the positive structural background and the neighboring oil-source fault is the key stratigraphic trap reservoir. Based on the analysis herein, the geological conditions influencing the accumulation of stratigraphic reservoir are mainly migration and accumulation, storage, trap and reservoir property. According to the evaluation of the geological conditions of stratigraphic traps in Jiyang depression, we establish the pre-drilling risk assessment method for stratigraphic trap, and then it is tested and verified. The results show that the evaluation results accords well with the actual drilling results, and the well of Jinping2, Chengdong112 with higher geological risk are all hydrocarbon accumulated, but the well of Chengdong111, Wang951 and other wells with low geological risk are not hydrocarbon accumulated.

Abstract:The Erlian basin is consisted of a group of middle Mesozoic and Cenozoic small fault lake basins, and it is geologically favorable for the formation of stratigraphic-lithologic reservoirs. Considering that these fault lake basins are characterized by small size, multiple sources, rapid deposition and abrupt facies belt change, this paper focuses on the formation process of sedimentary sandbodies distribution and analyzes the key factors controlling of sandbodies in terms of source material supply, transport pathway and sandbody distribution by means of research techniques of palaeostructure analysis, seismic sedimentary facies analysis and typical sedimentary sandbody analysis. It is indicated that the key factors controlling sandbodies distribution are the ancient material source, ancient valleys and slope breaks. Entry position and distribution of depositional systems are controlled by the sag margin and the internal ancient highlands. The transport pathways of sandbodies within the lake basins are controlled by ancient valleys formed by sag-controlling faults. In different types of slope break zones, the sandbodies present different characteristics of superposition and distribution. The an?cient material source, ancient valleys and slope breaks in fault sags are influenced mutually and have a significant effect on the forma? tion and distribution of sandbodies jointly.

Abstract:The E2s3 formation of Binnan oilfield is developed in basin rift epoch. Because of the adequate sediments, many kinds of turbidite sediment reservoirs are developed. However, due to the restriction of seismic data’s quality and facies change, great progress has not been made in the exploration of turbidite reservoirs in Binnan oilfield. This paper aims at practical problems of turbidite reservoirs identification and introduces a workflow: establishing sequence framework-analyzing seismic response characteristics (amplitude, continuity etc.)-attribute analysis with strata slice-spectral decomposition-log-constrained seismic inversion, and the issues above are perfectly solved. According to the seismic response, log and drilling characteristics, this paper divides the E2s3 formation into three sequences, and the turbite reservoirs is mainly developed in mid E2s3 & lower E2s3; the favorable turbidite reservoirs development sites are anticipated by using 90° phase rotation, strata slice and instantaneous amplitude technology, the result shows that the turbidite reservoirs is mainly developed in southeast and the neighboring areas of Binxian prominence; by application of S-Transformation, the initial seismic data is decomposed into 25, 30, 35, 40 and 45 Hz single-frequency data-bodies, among which, the 40 Hz single-frequency data-body shows a better resolving ability of turbidite reservoirs; and then, in combination with the log-constrained seismic inversion and 40 Hz single-frequency data-body, the vertical overlap features of turbidite sandbodies are clear, and favorable development sites of turbidite reservoirs are proposed.

Abstract:Inflow performance and optimization of artificial lifting way for horizontal wells in low permeability reservoir is the key to develop the horizontal wells for low permeability reservoir. Based on the classic Giger capacity formula, and adopting the hydropower similar principle and conformal mapping method to derive the productivity model and inflow performance equation of the hypotonic non-Darcy horizontal wells, the model has a higher accuracy after the field application verification, and the capacity influencing factors sensitivity of horizontal wells in low permeability reservoir is then analyzed. The analysis indicates that the horizontal well inflow performance variation is basically not affected by starting pressure gradient; and keeping pressure is the key to improve the efficiency of low permeability horizontal wells, the starting pressure gradient, permeability and coefficient of variation of the viscosity of the fluid are inversely proportional to liquid production, and the lower the pressure, the more obvious the effect; for the horizontal section length within 400 m, the ultimate production increases linearly with the horizontal length, the production drops and finally stabilized beyond 400 m;we use the equivalent weighting method and analytic hierarchy process to establish the lifting way preferred model, and the best lifting way of field wells is the electric submersible pump lifting.

Abstract:The correlation between the sulfate-reducing bacteria(SRB) in oilfield produced water and some factors such as oil content or suspended solids is revealed through systematic analysis of the present of SRB of produced water in the oil production process. The presence of SRB is an inherent feature of the produced water. And, the concentration of SRB always keeps stable in the produced water of a certain reservoir, however, it will vary with each production process. The on-way deterioration of water and viscosity loss of polymer caused by SRB have become the major problems in the development of oilfield. Inhabitation of SRB through adding bactericide can only relieve the deterioration temporarily. For the future oilfield production, some technical ideas and control strategies to the SRB prevention are proposed, the first is to open the treatment systems of re-injected oilfield wastewater, and apply air flotation rather than bactericides as much as possible.

Abstract:In-situ combustion is one of the effective methods used for heavy crude oil. The reservoir heterogeneity is bound to affect the development performance. Three kinds of heterogeneous model including permeability, thickness and geometry form are proposed based on the distribution characteristics of the sedimentary micro-facies of certain reservoir. Then, 18 reservoir simulation models are built by applying the method of reservoir numerical simulation. The development effectiveness of injection-production pattern caused by heterogeneity is studied. The research result shows that the initial and cumulative production is different due to different injectionproduction pattern at the same condition. In order to improve the development effectiveness of in-situ combustion, the injection-production pattern should be optimized. And, the impact of geometry form is the biggest, thickness secondly, then the permeability.

Abstract:For the threshold pressure gradient and the medium deformation characteristic in low permeability deformed medium sandstone reservoirs, an unsteady-state seepage model, which could predict the flood response time under different affecting factors more accurately, is established on the basis of the flow formula considering threshold pressure gradient and media deformation factor. The average formation pressure in the excited area has been solved by using repeated iteration method. And, the water flooding response calculation model in low permeability deformed medium sandstone reservoirs has also been established according to material balance method. The water flooding response is mainly affected by the well spacing, the average formation pressure in the excited region, the threshold pressure gradient and the media deformation factor. The flood response time sharply increases with the increase of well spacing or excited radius and the increase of water flooding response is getting faster with well spacing’s increment. The threshold pressure gradient or the media deformation factor greatly affects the water flooding response, and the greater the threshold pressure gradient or the media deformation factor, the longer the flood response time.

Abstract:After forty-three years water flooding development, the reservoir in Xing6 area is in high water cut stage of development, the scatter distribution of remaining oil and the poor development on thin and poor oil layers are present problems. On the basis of elaborate reservoir geological description, and using the skills of comprehensive description of the remaining oil, we analyze the features of remaining oil, as well as all types of layers’washing condition and adjustable sandstone thickness after second infilling in Xing6 area.In response to the sand layers with effective thickness under 0.5 m, the third infilling stage is implemented. Under the“three combinations”policy of optimizing well distribution, and through the adjustment of the well pattern, injection producer distance, well density,water flooding system, etc., the perfect injection and production systems are achieved to fully produce the remaining oil. The good results have been achieved in Xing6 area, and formed the matching infilling techniques.

Abstract:In view of the asymmetrical vertical fracture in the low permeability reservoir after fracturing development, and based on the steady seepage theory, and by means of the conformal transformation method, a prediction model for the finite-conductivity asymmetrical vertical fracture wells is established in the low-permeability gas reservoirs, and the various factors on the gas well productivity are analyzed. The result shows that, under the same bottom-hole pressure, the fracture asymmetry factor has little effect on the productivity of the gas well with asymmetrical vertical fracture. When the fracture conductivity capacity is small, there is great difference in the productivity of the fracture gas well with respect to fracture length or fracture asymmetry factor. And, when the fracture conductivity capacity is high, there is little difference in productivity with respect to variable fracture length or fracture asymmetry factor in gas well. The longer the fracture length, the less the fracture asymmetrical factor, and the greater influence on the fractured gas well productivity.

Abstract:There are many researches about the influence of the foam on gas-liquid relative permeability, but the influence of the temperature on foam relative permeability curve needs to be further studied. The curve reflecting the relationship between foam block pressure and gas-liquid flow rate ratio is measured at different temperature in this paper. So, the impact of the gas-liquid flow ratio and temperature on the block pressure is analyzed. The gas-liquid relative permeability curves both with the and without effects of foam are measured by using steady-state method in this paper. On this base, the flow rules of foam at different temperature are also characterized. The results indicate that the higher the experimental temperature, the better the sealing performance. And, both the foam block pressure and the blocking performance of foam can attain the highest degree in the range of gas-liquid flow ratio between 2 and 4. The foam has no effect on the relationship between the liquid relative permeability and the water saturation. The gas relative permeability,however, has a sharp decline under the action of foam. With the experimental temperature, the critical water saturation became higher with the increase of temperature and the moderate values of the gas relative permeability became lower with the increase of temperature.

Abstract:In response to the problems of fully developed micro-fractures in low permeability oil fields, severely heterogeneous reservoir and the fact that traditional profile control are less effective, the self-adaptive weak gel is developed. The static performance, sealing characteristics and displacement efficiency are evaluated through lab tests. The results show that the self-adaptive weak gel has good temperature-resistant and salt-resistant properties. When the salinity of formation water is 41 811.5 mg/L, the weak gel system can gelatinize rapidly in 38 hours, and the gel strength is 28 549 mPa?s under the condition of 70 ℃. Its plugging ratio is 84.08% and the recovery ratio reaches 12.1%. The field experiments of the well S in Ganguyi oilfeild indicate that the preferred path of water breakthrough of water injection well is controlled after profile control and flooding, and the injection pressure rises, at the same time, the water content of well group fell to 69.16% from 78.51%, and daily fluid production rate increases by 135.14%, while the daily oil production rate increases by 237.5%. The deep profile control technology of self-adaptive weak gel has good adaptability in fractured low permeability oil fields. It can enlarge the sweep volume of injected water and enhance oil recovery factor greatly, so it can provide reference for other similar reservoirs to obtain good performance on water control and oil increment.

Abstract:As the technology of horizontal well had been widely used in the gas and oil fields, the productivity forecast of horizontal wells will be of great importance. Based on the ellipse constant pressure surfaces near the wellbore, the author divides the seepage prob?lem of horizontal well into two parts, one is the problem in several ellipsoidal supply boundary near the wellbore, the other is the linear flow far from the well bore, based on the displacement between two similar flow mode and the law of equivalence percolation resistance,then eventually proposing a new productivity formula of horizontal well. Through case study, the results calculated by new formula has been compared with that calculated by the formulas of Borisov et al, it shows that the new result is more than the results calculated by conventional formulas, meanwhile, the new result has a small relative error compared to the practical oil production by only 10.09%.Analysis shows that this is because the resistance in ellipse drainage area is less than that in pseudo-circular drainage area, and the assumption of pseudo-circular will bring a great relative error. So, we can conclude that the new formula will not only predict the productivity accurately, but also accord with the practical flow mode of horizontal well.

Abstract:In order to study the production stimulation mechanism of water flooding by multi-stage fracturing horizontal well, the electrolytic simulation experiment of fractured horizontal well is designed according to the water and electricity resembling principle, and the pressure distribution and the productivity influence factors are studied. The experiment results show that the pressure contour is distributed in parallel in the middle of horizontal which has the fracture, and the fluid flow is unidirectional, it shows that the multi-stage fracturing horizontal well can improve the fluid flow characters and decrease the percolating resistance. The horizontal productivity can be enhanced by increasing the horizontal penetration ratio, the fracture numbers and penetration ratio, the angle between horizontal and fracture. The best parameters are as follows: the horizontal penetration ratio is 0.8, the fracture numbers are 6 (the space between fractures is 91 m), the fracture ratio is 0.25, the angle between the fracture and the horizontal section is 90 degree. The well pattern is staggered line-drive well network, and the ranges of those parameters which have effect on the productivity are 0.032, 0.024, 0.018, 0.018 and 0.004. The field application showed that the productivity of multi-stage fracturing horizontal well is 2 times than that of vertical well, and it is the effective development style for low permeability reservoir.

Abstract:In order to study the adaptation and effect of microbial flooding after polymer flooding pilot, the test was conducted as pilot project in Ng3 of Zhong1 area. The indigenous microorganisms are first activated and then filtrated; at the same time, 4 strains of functional bacteria are obtained, the bacteria are mass propagated at the reservoir environment, and the crude oil can be emulsified by the microbe. Meanwhile, the physical simulation experiment is studied under the pressure and temperature of the reservoir, and, the result indicates that the oil recovery is enhanced by 7.8%-8.3% by the bacteria. The field test indicates that the microbe is activated and the concentration of metabolism of acetate may reach 105 mg/L. The production dynamic is improved, and the oil recovery is enhanced by 1.27%, and the recovery factor in the pilot is increased by 4.7% to 57.8%.

Abstract:Due to the serious heterogeneity in plane, interlayer and layer, it is full of imbalances in injection-production pattern, and the production decline reaches 14.8% in Yi11 area of Bonan oilfield, so the technical treatment is needed to ameliorate the decline of the development. The non-stable injection and optimized liquid yielding are adopted to control the water and stabilize oil production in response to the high water cut and serious flooding in the major oil-production layers. Moreover, the water drive producing reserves are produced by improving and completion of well pattern in response to incomplete injection-production pattern. The interlayer problems are resolved by means of layer-oriented injection and plugging of high water cut layer. For the sand body edge and secondary oil-bearing layers, the reservoir reformation, intensive injection, individual layer production are adopted to enhance the reserve utilization. The development effect is remarkably improved. The production decline rate decrease to 4.1% and the recovery factor is further increased from 30.7% to 32%.

Abstract:Aiming at the problem of poor shear performance and salt tolerance of organogel, the deep anti-shearing and salt tolerant profile control agent is composed using anhydrous aluminum chloride and urea. The gelling behavior of the deep profile control agents is studied in this paper. The effects of concentration, temperature, and salinity on the gelling law are investigated. The application performances of the profile control agents, including the injectivity, plugging ability, and flushing resistance are evaluated. The results show that both the concentration and the temperature have great influence on the gelation time, and the gelation time can be adjusted from 16 to 824 h by adjusting the concentration of anhydrous aluminum chloride and urea. The inorganic salts including Na+，Mg2+，and Ca2+ have little effect on the gelation time. The salt tolerance, anti-shearing injectivity, plugging ability and flushing resistance of the gel system are very good, and the temperature limit is high as 80 ℃.

Abstract:Fractured-cavity carbonate reservoirs in Tahe oilfield have a serious heterogeneity, with numerous fissure, hole and cave.The bottom water is easy to breakthrough from high angle fracture, and it’s difficult to make water control for producing wells, so, the water plugging becomes important to oil production stabilization and water cut control. There is a significant progress of water plugging technology in fractured-cavity carbonate reservoirs in Tahe oilfield. The factors weight method for selecting well water plugging and five basic factors comprehensive analysis for plugging wells are formed. Three kinds of suitable plugging agents for fractured-cavity carbonate reservoirs are researched and developed. First, the soluble silicate, with good heat resistance and salt tolerance, is appropriate for well with small leakage and seam-hole reservoir. Second, the solidified grain, which has density selectivity and high strength, good heat resistance and salt tolerance as well, is suitable for fractured-cavity wells. Third, the organic-inorganic compound gel, with wateroil selectivity, is fit for fractured wells, horizontal wells and sidetracking wells. Based on plugging agent, the supporting water plugging technologies are formed and applied with good performance, including density selectivity, multistage slug holder plug and control pressure acidification.

Abstract:Moderate sand yielding technology can exploit crude oil with low cost and high efficiency, and improve the well productivity effectively. This technology needs to control sand concentration of the produced fluid in a certain range, which requires real-time monitoring wells sand conditions. In order to study the method of real-time monitoring of the sand signal, the laboratory has developed a system of high frequency vibration signal used for monitoring the signal of sand. Through the time-frequency analysis of vibration signals of different sizes of sand hitting on the pipe wall in the laboratory simulation of sand production, the frequency range of the characteristic frequency of vibration signals reflecting the information of sand is screened out between 10-12 kHz, which proves the feasibility of the pipeline high-frequency vibration signal monitoring system. It has an important guiding significance for further study on sanding monitoring.