Determination of Optimum Rate in a Condensate Well with a Case of a Wellbore Liquid Loading

Condensate reservoirs are mostly pressure sensitive and keeping the pressure above the dew point pressure in the reservoir is critical to avoid condensate banking in the reservoir. If it occurs, production is highly inhibited and the well may ultimately quit on production under liquid loading. Fluid ratios are important in the management of condensate wells and most critical is the Gas Liquid Ratio (GLR). There is a certain GLR that below it, there will be a liquid loading in the wellbore that could quit the well. Each fluid rate goes with a GLR and the point where there is a reversal of the GLR or CGR trends may present a case of loading scenario and that is taken as the determination reference point. When a condensate well shows an improvement of water cut as the choke bean size is reduced does not necessarily signify a healthy situation and neither a one-point higher water cut with increase in choke bean size mean a water coning situation. When a liquid loading well is beaned up, there is early signs of water coning in the production data but this is just a wellbore production and the BS&W improves as the production rate is further increased. Further investigation is necessary to separate the challenge of water conning from the challenge of too low Gas rate which causes the loading of the liquids in the wellbore. That is the operating envelop to manage condensate well rates: rates too low with a possibility of a liquid loading and rates too high that depicts a case of water conning when water is close to the perforation. This band must be completely exploited to turn the production curve in the positive. This paper provides a strategy to recover a condensate well production with a challenge of liquid loading using a case study. The degree of the severity of the liquid loading can be represented using a power law model with the gradient being the level of severity of the loading. The production improvement is greater than nβ percent where n is the quadratic model number 2 and β is the product of the graphical and Lagrangian-Quadratic alpha parameters. The optimum rate can be determined using the Lagrange Multiplier optimization method to effectively extend the production life of the well.

Optimization rate of urea fertilizer for one-year-old pepper (Piper nigrum L.) parent plant

Optimum maintenance is required to get a high-quality parent plant. One of themaintenances is fertilization to ensure the optimal growth of the pepper parent plant. This studyaimed to obtain the optimum rate of urea fertilizer for a one-year-old of the pepper parentplant. The field experiment used a single factor in a randomized block design (RBD) with fiveurea rate levels, and each treatment was repeated three times. Treatment levels of urea rate,namely 0 g plant-1 year-1, 100 g plant-1 year-1, 200 g plant-1 year-1, 300 g plant-1 year-1 and400 g plant-1 year-1. The rate of urea influenced the number of internodes and leaf area of thepepper parent plant. The rate of 315 g plant-1 year-1 urea is the optimum rate for the growth ofthe number of the branch of a one-year-old pepper parent plant.

Rice Husk Compost Production and Use in Mitigating Ammonia Volatilization from Urea

Using value-added products such as compost in farming systems could enable optimization of nitrogen (N) fertilizers whose world-wide demand is on the increase. The objectives of this study were to: (i) produce compost through co-composting rice husk (RH) with chicken dung slurry (CDS), chicken feed, and molasses, (ii) determine the effects of optimum rate of urea and RH compost on minimizing ammonia (NH3) volatilization, and (iii) determine total N, exchangeable ammonium (NH4+), and available nitrate (NO3−) retained in soil following co-application of urea and RH compost. Compost was produced for 60 days by mixing RH, CDS, chicken feed, and molasses at a ratio of 20:1:1:1. The color of RH compost was dark brown and had significant amounts of major nutrients such as N (1.15%), phosphorus (3101 mg kg−1), potassium (2038 mg kg−1), calcium (863 mg kg−1), magnesium (276 mg kg−1), organic matter (OM) (60.67%), organic carbon (35.17%), and humic acids (5.87%). The C/N ratio of the RH compost was 30. The electrical conductivity and pH of the RH compost were 2.79 µS cm−1 and 6.55, respectively, and they were not phytotoxic because paddy seeds were successfully germinated in all of the RH compost extractants. The high cation exchange capacity (CEC) of the RH compost (100.67 cmolc kg−1) at the end of composting was one of the determinant factors that controlled NH3 loss from urea. The effectiveness of the RH compost in minimizing urea-N loss was determined using a close-dynamic air flow system. The RH compost significantly minimized NH3 volatilization because of the high affinity of the RH compost for NH4+. An attestation of this reaction was that the high negative charges due to high CEC and OM of the RH compost temporarily protected NH4+ from being transformed into NH3 gas. Further evidence is the higher soil total N and exchangeable NH4+ for the treatments with RH compost than with urea alone. High quality compost can be produced from RH to reduce urea-N from being lost from urea. For the optimum rate, co-application of 60 g RH compost and 2.9 g urea per trough is recommended to mitigate NH3 volatilization instead of the existing practice (7.3 g urea alone per trough).

A Micropropagation Protocol for the Endangered Medicinal Tree Prunus africana (Hook f.) Kalkman: Genetic Fidelity and Physiological Parameter Assessment

Prunus africana is an endangered medicinal plant and hence new propagation methods are urgently required to increase its populations. Unfortunately, propagation through seeds is challenging due to its long flowering cycle and recalcitrant seeds. We developed a protocol for micropropagation using nodal segment explants. A woody plant medium supplemented with vitamins, 15 g L−1 sucrose, and 1.0 mg L−1 6-benzylaminopurine (BAP) supported the optimum rate (100%) of axillary shoot initiation. Supplementation with 15 g L−1 sucrose and 1.5 mg L−1 indole-3-acetic acid (IAA) provided the optimum rate (75%) of root initiation. Rooted plantlets were successfully planted in sterilized horticultural soil containing perlite (2:1 v/v) and the survival rate was 98% following acclimatization. The photosynthetic rate assessed using FlourPen FP110 series showed that the ratio of variable fluorescence to maximum fluorescence mean value for in vitro regenerated P. africana (0.830 ± 0.0008) was similar to that of the maternal P. africana plant (0.825 ± 0.005), indicating similarity in their photosynthetic performance; a pivotal process for growth and development. The Fourier transform near-IR (FT-NIR) spectrometer analysis of the in vitro regenerated and the maternal P. africana plant samples exhibited homogeneity in the absorbance peaks at 8,273, 6,344, and 4,938–4,500 cm−1 associated with lipids, starch, and proteins. The genetic fidelity of regenerated plants was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Our protocol is suitable for use in large-scale P. africana to meet the increasing demands for it in the global market.

PENGARUH DOSIS PUPUK KASCING DAN NITROGEN TERHADAP PERTUMBUHAN DAN HASIL TANAMAN SELADA (LACTVCA SATIVA L.) VAR GEORGIA

The low of growth and yield of lettuce is quite often caused by the low of soil fertility, especially nitrogen and C-organic content. Poor soil physical properties also contribute to the cause of low yield of lettuce. Improved soil physical and chemical properties by adding casting fertilizers and nitrogen are expected to be able to increase the yields of lettuce. The field experiment was conducted in Candikuning village, district of Baturiti, Tabanan regency, from October 2005 to January 2006. The objective of the experiment was to study the effect of casting fertilizer and nitrogen rates on the growth and yields of lettuce. A randomized complete block design was used in this experiment and two treatment factors were imposed. Those two treatment factors were rates of casting fertilizers (i.e. 0, 10, 20 and 30 t ha"1 ) and rates of N (i.e. 0, 92, 138 and 184 kg N ha"1), which were arranged factorially and repeated three times. Results of the experiment indicated that interaction between casting fertilizer and nitrogen rates did not significantly affect the yields of lettuce. The rates of N only significantly affected several growth variables and the oven-dry weight of heads plant-1. Increased rates of N from 0 to 92 kg N ha-1 significantly resulted in the oven-dry weight of heads of 2.798 g plant-1 which was 13.9% higher than that of 0 kg N ha-1. Rates of casting fertilizer significantly affected head diameter and the oven-dry weight of heads plant"1 and ha-1. Increased rates of casting fertilizer from 0 to 10 t ha-1 gave the oven-dry weight of heads as much as 0.232 t ha"1 or 9.43% higher than the weight given by the rate of 0 t ha-1. The effects of rates of casting fertilizer and N were only significant on several soil physical properties. The relationship between rates of casting fertilizer and yields of lettuce was quadratic (Y = 0.21135 + 0.0032 X - 0.001 X2 ; R2 = 0.981). The optimum rate of casting fertilizer was 16.0 t ha-1 with the maximum oven-dry weight of heads of 0.237 t ha-1, meanwhile, the optimum rate of N had not obtained in this experiment.

HABITAT AND BIOLOGICAL CHARACTERISTIC OF TILAPIA (Oreochromis niloticus) IN BATUR LAKE

Study on habitat and biological characteristic of Tilapia (Oreochromis niloticus) in Batur lake have been carried out in Februari until November 2011. The result investigations of water quality parameters at six research station showed that support for the life of Tilapia. Exploitation rate of Tilapia was exceed the optimum rate (over fishing). Tilapia in Batur lake was able to reach 41,45 cm on size with growth rate (K) 0,52 per year. Tilapia in Batur lake was spawn throughout the year (IKG < 20%) with the top of spawning on March and July. The size of first maturity was 17,559 – 20,408 cm. Tilapia in Batur Lake was herbivore to omnivore as the first consumer level with generalis pattern.