Controlled Frac Height Growth Technique to Avoid Contacting Water-Bearing Layer

Many techniques have been used to model, diagnose and detect fracture dimension and propagation during hydraulic fracturing. Diagnosing fracture dimension growth vs time is of paramount importance to reach the desired geometry to maximize hydrocarbon production potential and prevent contacting undesired fluid zones. The study presented here describes a technique implemented to control vertical fracture growth in a tight sandstone formation being stimulated near a water zone. This gas well was completed vertically as openhole with Multi- Stage Fracturing (MSF). Pre-Fracturing diagnostic tests in combination with high-resolution temperature logs provided evidence of vertical fracture height growth downward toward water zone. Pre-fracturing flowback indicated water presence that was confirmed by lab test. Several actions were taken to mitigate fracture vertical growth during the placement of main treatment. An artificial barrier with proppant was placed in the lower zone of the reservoir before main fracturing execution. The rate and viscosity of fracturing fluids were also adjusted to control the net pressure aiming to enhance fracture length into the reservoir. The redesigned proppant fracturing job was placed into the formation as planned. Production results showed the effectiveness of the artificial lower barrier placed to prevent fracture vertical growth down into the water zone. Noise log consists of Sonic Noise Log (SNL) and High Precision Temperature (HPT) was performed. The log analysis indicated that two major fractures were initiated away from water-bearing zone with minimum water production. Additionally, in- situ minimum stress profile indicated no enough contrast between layers to help confine fracture into the targeted reservoir. Commercial gas production was achieved after applying this stimulation technique while keeping water production rate controlled within the desired range. The approach described in this paper to optimize gas production in tight formation with nearby water contact during hydraulic fracturing treatments has been applied with a significant improvement in well production. This will serve as reference for future intervention under same challenging completion conditions.

Dry Bean (Phaseolus vulgaris L.) Crop Water Production Functions and Yield Response Factors in an Arid to Semi-Arid Climate

HighlightsDeficit irrigation negatively affected dry bean yield and yield components.Excess irrigation increased crop ETc but not dry bean yield.Soil moisture fluctuation was greater in the top 0.3 m of the soil profile compared to deeper depths.Crop water production function had a slope of 18.9 kg ha-1 mm-1 and threshold crop evapotranspiration of 171 mm.Dry bean crop was found to be sensitive to water stress (yield response factor Ky = 1.94).Abstract. Under changing climate conditions and declining water resources, understanding crop response to water stress is critical for effective irrigation management. The objectives of this study were to quantify dry bean (Phaseolus vulgaris L., cv. Othello) soil moisture dynamics, crop evapotranspiration (ETc), and yield response factor and to develop dry bean irrigation and crop water production functions (IWPF and CWPF). Five irrigation treatments, i.e., full irrigation (FIT), 75% FIT, 50% FIT, 25% FIT, and 125% FIT, were evaluated using a randomized complete block design (RCBD) with three replications for three years (2017, 2018, and 2019) in the arid to semi-arid intermountain region of Powell, Wyoming. The results showed a significant influence of irrigation on dry bean soil moisture dynamics and ETc. The dry bean crop showed a greater soil moisture fluctuation in the top 0.3 m of the soil profile compared to 0.6 m and at 0.9 m. ETc ranged from 187 to 438 mm, from 190 to 409 mm, and from 217 to 398 mm in the 2017, 2018, and 2019 growing seasons, respectively. A positive two-segment relationship was observed between dry bean seed yield and cumulative irrigation water applied. The average cumulative seasonal irrigation of 310 mm resulted in maximum seed yield. For all three years, the seed yield increased linearly with ETc. Combining the data from the three years resulted in a CWPF with a slope of 18.9 kg ha-1 mm-1 and an offset of 171 mm of ETc (i.e., the ETc required for crop establishment before any seed yield is produced, or threshold ETc). Moreover, the dry bean crop was found to be sensitive to water stress (Ky = 1.94). These results indicated that under the typical semi-arid to arid climate conditions of the intermountain region of Wyoming, deficit irrigation of dry bean may not be a viable strategy because the yield loss outweighs water-saving benefits. Keywords: Dry bean, Crop evapotranspiration, Crop production function, Irrigation water production function.

Numerical Simulation Research on Influencing Factors of Post-Fracturing Flowback of Shale Gas Wells in the Sichuan Basin

The horizontal well multistage hydraulic fracturing technology is the most effective way to exploit shale gas resources. Compared with conventional reservoir fracturing, the flowback rate of a fracturing fluid in a shale reservoir is extremely low, and a large amount of fracturing fluid remains in the formation. Therefore, the research on the mechanism of shale reservoir fracturing fluid flowback process will contribute to laying a theoretical foundation for improving the effect of the innovation for increasing output of shale gas wells. Based on the shale in the Sichuan Basin, this study first describes basic experiments on physical properties such as the porosity, permeability, mineral composition, wettability, and microstructure. The physical properties of shale reservoirs were also analyzed, which laid the foundation for subsequent modeling. Second, CMG software is used to establish a numerical model that fits the characteristics of the flowback process. The effect of reservoir properties, fracturing parameters, drainage–production system, chemical permeability on gas and water production in the flowback process and their mechanisms are also analyzed. According to most numerical simulation results, the lower cumulative gas production will be with the higher cumulative water production which means the higher flowback rate. The pursuit of only a high flowback rate is not advisable, and the development of the drainage–production system requires reasonable control of the fracturing fluid flowback rate. This study provides a theoretical basis for the optimization of shale gas drainage–production system after hydraulic fracturing.

Prototype System Water Level Reservoir untuk Pengendalian Kelebihan Air dengan Mikrokontroller Arduino Uno R3

PDAM Loa Kulu Branch still uses sticks or poles as an indicator of the water level in the reservoir. Reservoir is a place to store clean water production from PDAM, the weakness of using sticks or poles is when the operator does not monitor continuously causing air loss when production becomes large. The goal of the study was to design a water-level prototype to control excess water in the reservoir. The method used is a prototype with the stage of gathering information through interviewing PDAM staff, creating and repairing prototypes and testing prototypes. The test used hardware consisting of Arduino uno r3, ultrasonic sensor hc-sr04, flowmeter sensor yf-s201, 16 x 2 lcd, relay module, buzzer, solenoid valve 12 V_dc, pump 12 V_dc and display measurement results in the visual studio application 2019. Our findings are that the length of reservoir charging with an average input discharge of 3.6 liters / minute is 2.93 minutes. As for the length of emptying the reservoir with an average output discharge of 1.06 liters / minute is 12.10 minutes. The conclusion of this study is that the system can monitor the water level inside the reservoir automatically and know the time needed for the feeling and emptying process of the reservoir.